The Climatic Causation of Consumption, 
- WITH - 
Tables and Diagrams Representing the Same. 
Read in the Section of State Medicine at the Fortieth Annual Meeting of the American 
Medical Association, Newport, R. 1., fline, iBBg. 
HENRY B. BAKER, M.D., 
OF FANSING, MICH. 
Reprinted from “The Journal of the American Medical Association,” January 18 and 25, 
and February 1, iBpo. 
CHICAGO: 
Printed at the Office of the Association. 
1890. Henry B Baker, M.D. 
PRESIDENT OF THE AMERICAN PUBLIC HEALTH ASSOCIATION 
1889-90 
PRESENTED TO THE MEMBERS OF THE A. P. H. A. WITH 
THE COMPLIMENTS OF 
The Annals of Hygiene THE CLIMATIC CAUSATION OF CONSUMPTION, WITH TABLES AND DIAGRAMS 
REPRESENTING THE SAME, 
Read in the Section of Stale Medicine, at the Fortieth Annual Meeting of the American Medical Association, June, 1889. 
HENRY B. BAKER, M.D., 
OF LANSING, MICH. 
In order that one may be justified in bringing 
here an elaborate paper with extensive tables and 
illustrative diagrams, it is incumbent on the 
writer to make sure that he has either facts of 
importance which have not been published, or 
such new mode of grouping facts previously 
known as shall yield new and useful knowledge, 
especially when, as in this instance, the title of 
the paper is similar to that of other papers the 
same person. Therefore I hasten to assure you 
that there are included in and with this paper 
facts which, so far as I know, have not been pub- 
lished, and others which have not in connection 
with this subject.1 
This grouping ot evidences on this subject has 
for its main purpose the learning whether three 
important generalizations relative to consumption 
are antagonistic to each other, as has commonly 
been supposed, or whether there are facts which 
serve to bind them together and harmonize them, 
and thus make each of the classes of facts upon 
which these generalizations are based tend to 
support a still wider generalization, which shall 
include all the preceding ones. 
The general law to which I shall first give at- 
tention is the one established many years ago by 
Dr. Henry I. Bowditch, of Massachusetts, and 
nearly the same time in England by Dr. Bucha- 
nan. I refer to the generalization that residence 
on low, moist ground tends toward the occurrence 
of consumption. 
Next in order, and in connection with the first, 
I shall deal with a generalization to which, dur- 
ing recent years, I have myself been asking at- 
tention. I refer to the proposition that exposure 
to the inhalation of cold dry air tends toward the 
production of consumption—that, in fact, this is 
a controlling cause of the disease. 
Thirdly, the dominant generalization of our 
own time, that consumption has one specific cause, 
and that cause the bacillus tuberculosis, will be 
considered, or at least acknowledged. 
At first thought these three propositions appear 
to be incongruous, and I think there is generally 
an idea that only one of them can be true; but I 
may here anticipate one conclusion in this paper 
by saying that it seems to me that each one of 
these propositions rests upon a secure foundation, 
and that as soon as this is accepted as established 
it will be possible to hold a much more complete 
and useful view of the causation of consumption 
than has previously been possible—a view which 
shall recognize the facts (i) that inoculation of a 
susceptible animal with the bacillus tuberculosis 
generally tends to cause consumption in that ani- 
mal ; (2) that, notwithstanding a wide dissemina- 
tion of this specific cause, accidental inoculation 
with it, or its permanent lodgment in the human 
1 List of Tables and Diagrams forming the Bases of the Evidence 
in this paper: 
Table i and diagram i—Croup, and temperature in Massachu- 
setts. 
Table 2 and diagram 2—Croup, and absolute humidity in Massa- 
chusetts. 
Table 3 and diagram 3—Consumption, and temperature in Mas- 
sachusetts. 
Table 4 and diagram 4—Small pox, and temperature in Massa- 
chusetts. 
Table 5 and diagram s—Diphtheria,5—Diphtheria, and temperature in Massa- 
chusetts. 
Table 6 and diagram 6—Pneumonia, and temperature in Massa- 
chusetts. 
Table 7 and diagram 7—Scarlatina, and temperature in Massa- 
chusetts. 
Table 8 and diagram B—Temperature,8—Temperature, and sickness from pneu- 
monia in U. S. armies. 
Table 9 and diagram 9—Sickness from consumption in white 
troops, U. S. army, and temperature, 1862-5. 
Diagram 10—Temperature, and deaths from phthisis in London, 
thirty years. 
Diagram 11—Temperature, and sickness from consumption in 
Michigan. 
Diagram 12—Bronchitis, and temperature in London. 
Diagram 13—Sickness from croup, and temperature in Michi- 
gan. . 
Diagram 14—Temperature, and sickness from respiratory dis- 
eases in India, three years. 
Diagram 15 Sickness from influenza, and temperature in 
Michigan. 
Diagram 16 Sickness from tocsilitis, and temperature in 
Michigan. 
Diagram 17—Temperature, and sickness from bronchitis in 
Michigan. 
Diagram 18—Sickness from pneumonia, and temperature in 
Michigan. 
Diagram 19—Absolute humidity, and sickness from pneumonia 
in Michigan. 
Diagram 20—Pneumonia, and temperature in London, England 
Diagram 21—Temperature, and sickness from scarlet fever in 
Michigan. 
Diagram 22—Deaths from small-pox, and temperature in Lon- 
don, England. 
Table 23 and diagram 23—Deaths from consumption in white 
troops in U. S. armies, and temperature. 
Table 24 and diagram 24—Sickness from diphtheria, and tem- 
perature in Michigan. 2 
organism, is more favored under certain climatic 
conditions than under others; (3) that even after 
its introduction and lodgment in the organism, 
residence in cellar-like places tends to make the 
disease more fatal than does residence in more 
elevated, well-drained, warm and sunny places. 
It has been generally understood that there are 
influences associated with low and wet localities, 
and, by contrast, with high and dry localities, 
which it is especially important for mankind to 
learn and heed ; and yet the systematic attempts 
to obtain a scientific knowledge of the nature of 
these influences, or even their extent, have been 
very few. Some years ago two prominent phy- 
sicians, one in this country, Dr. Henry I. Bow- 
ditch, and one in England, Dr. G. Buchanan, al- 
most simultaneously undertook to learn the influ- 
ence of residence upon low, wet ground on that 
most important of all diseases, consumption. 
More recently Dr. William Pepper has attempted 
to collect the evidence on this subject throughout 
the State of Pennsylvania. 
health of the United States army, strongly supporting 
the idea of the existence of the same law and the opera- 
tion of it over the whole of the United States. 
8. Results of my own practice since I first became con- 
vinced of the truth of the law, said results consisting of 
(a) statistics from my private medical record; (b) results 
actually derived from my choice of localities for con- 
sumptive patients, based on a belief in the law.3 
DR. BUCHANAN’S INVESTIGATIONS, IN ENGLAND. 
Dr. Buchanan’s very important contribution to 
our knowledge of this subject is so well summa- 
rized by Dr. William Pepper, that it seems best 
to quote from him, as follows: 
The ninth and tenth reports of Mr. John Simon, Med- 
ical Officer of the Privy Council, contain the results of 
Dr. Buchanan’s work, which was carried on in 1865, ’66 
and ’67. Through this investigation it was discovered 
that in certain English towns where the drying of the 
subsoil had been accomplished by the construction of 
sewers, etc., and where the water supply had been im- 
proved, the mortality from phthisis had decreased. In 
Salisbury the death-rate from phthisis had fallen 49 per 
cent.; in Ely, 47 per cent.; in Rugby, 43 per cent.; in 
Banbury, 41 per cent.4 In towns where no improvements 
had been made, or where the conditions were already 
good, there was no such corresponding change in the 
death rate. 
Dr. Buchanan summarizes the facts brought out in 
his investigation of phthisis in Surrey, Kent and Sussex, 
as follows: 
There is less phthisis among populations living on 
pervious soils than among populations living on imper- 
vious soils. 
There is less phthisis among populations living on 
high-lying pervious soils than among populations living 
on low-lying pervious soils. 
There is less phthisis among populations living on 
sloping impervious soils than among populations living 
on flat impervious soils. 
This connection between the influence of soil and 
phthisis was established by— 
1. The general agreement in phthisis mortality between 
districts that have common geological and topographical 
features that are of a nature to affect the water-holding 
quality of the soil. 
2. By the existence of a general disagreement between 
districts that are differently circumstanced in regard to 
such features; and 
3. By the discovery of pretty regular concomitancy in 
the fluctuation of the two conditions from much phthisis 
with much wetness of soil to little phthisis with little 
wetness of soil.5 
In his Tenth Report as Medical Officer, for 1867, Dr. 
Buchanan says: 
But the connection between wet soil and phthisis came 
out last year in another way, which must here be recalled 
—(d) by the observation that phthisis had been greatly 
reduced in towns where the water of the soil had been 
artificially removed, and that it had not been reduced in 
other towns where the soil had not been dried. 
5. The whole of the foregoing conclusions combine 
into one—which may now be affirmed generally, and not 
only of particular districts—that wetness of soil is a 
cause of phthisis to the population living upon it. 
DR. BOWDITCH’S INVESTIGATIONS IN MASSA- 
CHUSETTS. 
Dr. Bowditch has said that the two following 
propositions contain the essential points of his 
address on this subject: 
First.—A residence on or near a damp soil, whether 
that dampness be inherent in the soil itself, or caused bv 
percolation from adjacent ponds, rivers, meadows, 
marshes or springy soils, is one of the primal causes of 
consumption in Massachusetts, probably in New Eng- 
land, and possibly in other portions of the globe. 
Second.—Consumption can be checked in its career, 
and possibly, nay probably, prevented in some instances 
by attention to this law.2 
These lines of proof, or argument, are drawn from the 
following sources: 
1. Massachusetts State registration reports. 
2. Medical opinion of Massachusetts, as embodied in 
the returns made to me, as a committee of this Society, 
these returns consisting of written reports from resident 
physicians of 183 towns. 
3. Actual statistics of deaths from consumption, re- 
ceived from such correspondents. Some of these statis- 
tics are but incidentally mentioned, while others are 
from towns, districted and carefully examined with refer- 
ence to the relative prevalence of consumption in the dif- 
ferent districts. In some of the most important of these 
the examination was made without my correspondent or 
myself being aware of the existence of any law such as 
that which I shall present at this time. 
4. Peculiarities of certain towns and of villages in the 
same townships, in some of which consumption is quite 
prevalent, and in others much less so, these differences 
being connected most closely with corresponding differ- 
ences in the amount of moisture of the soil of said places. 
5. Certain well-known houses which, in various towns, 
are known by the inhabitants and physicians to have 
been long noted as the abode of consumption, and in 
some of which several families have been, during the past 
fifty years, cut off by the disease without the least sus- 
picion on the part of the occupants of the fatal position 
in which the houses were placed. 
6. Confirmatory facts, statistics and opinions from 
Rhode Island, Maine and New Hampshire. 
7. The medical statistics given in the report on the 
Dr. Buchanan quotes from the Seventh Annual 
Report of the Registrar General for Scotland, from 
which I extract the following 
3 Med. Com. Med. Soc,, Vol. x, No. ix, 1862, pp. 68—70. 
4 “Worthing, 36; Leicester, 32; Macclesfield, 31; Newport, 32; Chel- 
tenham, 26. Bristol, 22; Dover, 20; Warwick, 19; Croydon, 17; Cardiff, 
17; and Merthyr, n;” according to the Medical Officer, page 13, 
Tenth Report Med. Officer of the Privy Council, 1867. 
2 Med. Com. Mass. Med. Soc., Vol. x, No. 11, 1862, p. 67. 
STrans. Am. Climatolog. Assoc., May, 1886, N. Y., 1887, p. 89. 
6 Tenth Report Medical Officer, Privy Council, 1867, p. 109. 3 
Let us see how such an explanation would agree with 
the very different proportion of deaths from consumption 
which occur in the eight principal towns of Scotland. 
Taking a five years’ average (1857 to 1861 inclusive), it is 
found that, supposing all these towns are brought to an 
uniform population of 100,000 persons, there died annu- 
ally from consumption 206 persons in Leith, 298 in Edin- 
burgh, 310 in Perth, 332 in Aberdeen, 340 in Dundee, 383 
in Paisley, 399 in Glasgow, and 400 in Greenock. The 
fact is, that if each town had been arranged in the order of 
comparative dryness of its site, they would almost have 
arranged themselves in the above position—Leith and 
Edinburgh the most free from consumption, and also 
having the dryest sites; Glasgow and Greenock the most 
ravaged by that disease, and beyond all comparison situ- 
ated on the dampest sites. The above fact, then, with 
regard to the towns, corroborates, in the most striking 
manner, the conclusions of Dr. Bowditch, and should be 
a valuable help to the sanitary reformers, as to the very 
important measures which it is their more especial prov- 
ince to carry out.7 
It cannot be maintained that [all] deaths which used 
to be registered as phthisis are now included under lung 
diseases, because although there is an increase under the 
latter head, it is by no means equal to the decrease under 
phthisis. 
Dr. Kelly, therefore, still claims that there has 
been an undoubted decrease of consumption in 
his jurisdiction. 
Dr. Kelly’s results reinforce the evidence here- 
tofore collected, as to the influence of nearly all 
sanitary improvements in decreasing consumption, 
but they do not seem to me to have any force 
toward breaking down the evidence collected by 
Drs. Bowditch and Buchanan. 
DR. PEPPER’S INVESTIGATIONS, IN PENNSYE- 
VANIA. 
Dr. Pepper’s “Climatological Study of Con- 
sumption in Pennsylyania’’ seems to have been 
well planned, and carefully executed, but it did 
not yield results as convincing on the subject of 
the relation of soil moisture to consumption as 
did the investigations by Drs Bowditch and Bu- 
chanan, probably because of less perfect records 
of vital statistics in Pennsylvania, and perhaps 
also because of less attention having been given 
to the subject by local physicians in that State. 
A few selections may be instructive: 
It will be observed at once that those portions of the 
State where phthisis is rarest are the most elevated, hav- 
ing a general altitude of 1,500 to 2,000, or, better still, of 
2,000 to 3,000 feet; while, in proportion as we enter dis- 
tricts of lower general altitude, we find correspondingly 
increasing rates of mortality from consumption.5 
It may be noted that in Erie county, which has consid- 
erable average elevation, the mortality may be influenced 
by the proximity of the lake, and by the presence of a 
considerable body of low, wet land. 
It will be seen further on, in the more minute study we 
have been able to make of Philadelphia, that the influ- 
ence of elevation and of density of population appears to 
be considerable, and in accordance with what we have 
above stated.9 
Dr. Bowditch and Dr. Buchanan each gathered 
evidence, from several sources, the combined force 
of which was very great, and after their results 
were united their conclusions were irresistible. 
As they have never been successfully controvert- 
ed, it seems probable that the laws which they 
formulated will .stand as a secure foundation upon 
which we may safely build. Wm. Pepper, M.D., 
UU.D., the distinguished Provost of the Univer- 
sity of Pennsylvania, has said: 
It is manifestly difficult to subject this theory to search- 
ing and conclusive investigation; but, so far as investiga- 
tion has been made in other portions of this country or 
abroad, the evidence has tended to confirm Dr. Bowditch’s 
position.10 
But, if the grand truth, for which we are so 
much indebted to him, is really a truth, how 
comes it that the great reduction in consumption 
which should have followed its discovery has 
been as yet so little realized ? There are, prob- 
Referring to the conclusions based upon these 
investigations by Drs. Bowditch and Buchanan, 
Dr. R. Thorne Thorne, in his ‘ ‘ Progress of Pre 
ventive Medicine during the Victorian Era,” page 
51, says : 
I am aware that, in his sixth report (1879) on the Com- 
bined Sanitary District of West Sussex, Ur. Charles Kel- 
ly, basing his views on certain experiences derived from 
that rural area, has expressed a doubt as to the correct- 
ness of these conclusions. He says that the phthisis death- 
rate has been “ distinctly lowered ” in that district “in 
recent years,” “ while ver}' little, if any, change has taken 
place during the same period in the drainage of the soil.” 
Without entering into any criticism of some of the statis- 
tical data brought forward by Dr. Kelly in support of his 
views, I would here merely note, 1, that a large amount 
of agricultural drainage which had then already been ef- 
fected throughout the kingdom would be expected to 
have produced a very similar result in rural districts to 
that brought about by sanitary drainage in towns; and 2, 
that Dr. Kelly offers no explanation of the definite and 
striking relations shown by Dr. Buchanan to have exist- 
ed between the amount of diminution of phthisis death- 
rate and the extent and permanence of the lowering of 
subsoil water. 
I have studied, with great interest, Dr. Kelly’s 
“ Sixth Annual Report,” for West Sussex, pub- 
lished in 1880, as also one or two of his recent re- 
ports ; and although I do not conclude that the 
facts and considerations he publishes controvert 
those published by Drs. Bowditch and Buchanan, 
they are of value, and especially in suggesting 
that coincidently with considerable progress in 
improved sanitary conditions of the surroundings, 
such as improved water supply, drainage, sewer- 
age, etc., and improved methods of living, there 
has been apparently a great lessening of the mor- 
tality from consumption. Dr. Kelly says : 
The great difference in the amount of consumption is 
probably dependent upon several causes. The improved 
state of the cottages, the rise of wages leading to the 
children being better clothed and fed, the increase in 
railway communication, which tends to diminish inter- 
marriage, and to cause more interchange of population 
—all these changes, social as well as sanitary, have had 
their share in the improvement. 
In his Fourteenth Annual Report, page 188, 
Dr. Kelly says: 
8 Trans. Am. Climatological Assoc., May, 1886. New York, 
1887, p. 98. 
/Tenth Report Medical Officer, Privy Council, 1867, p. no. 
9 Page 99. 
10 Trans. Am. Climatological Assoc., 1887, p. 88. 4 
ably, several reasons, such as the slow progress 
which any such truth has in gaining acceptance, 
even among the thinking classes; but, in my 
opinion, one chief reason for the non-acceptance 
of, and for the non-action in accordance with this 
great discovery, was the fact that no one knew 
the reason why residence on or near low, wet soil 
was a prominent cause of consumption. The as- 
sertion and proof that this was a true law, when 
no one could imagine a reason why, has not led 
to its acceptance in such a hearty manner as to 
make it a strong factor in controlling the actions 
of residents of even New England. So that, al- 
though the death-rate from consumption in many 
parts of New England has steadily declined, it 
has not declined as fast as a knowledge of such 
an important general law as that propounded by 
Dr. Bowditch might have led one to expect; and 
it is with a feeling of sadness that one knowing 
this must now read the lines written by Dr. Bow- 
ditch over a quarter of a century ago, and which 
glow with lofty sentiments of manly enthusiasm. 
Not but that his work was well and nobly done, 
but the sadness comes because mankind is so slow 
to heed the warnings of its best prophets. Dr. 
Bowditch said : 
When I revolved in my mind the possibility of this 
being an exact representation of a great truth, and then 
thought of the vast influence the thorough knowledge of 
it must have upon our professional practice, and of the 
beneficial effects upon public hygiene that would perhaps 
result, in future, from an intelligent obedience to it by 
the community at large, it was the happiest and most 
satisfactory moment of my professional life. I remem- 
bered that over twenty thousand11 consumptive patients 
had died in Massachusetts during the previous five years. 
I asked myself these questions; Supposing this town- 
ship represents the various townships of the State, and 
that they all have their varieties of soil, then if this town- 
ship’s statistics are true, and at least twice as many die 
in the wet as in the dry districts, may not similar results 
have occurred and perhaps be still occurring all over the 
State in which these twenty thousand human beings 
have been slain? Having arrived at this point, you will 
not be surprised at my asking, still further, this pregnant 
question: If our fathers and we had paid greater atten- 
tion to this law, and we had always resided in dry locali- 
ties, leaving the lower and moister for the purposes of 
business, perhaps, during the day, or for agriculture, 
should we not be saving over one thousand lives annu- 
ally in Massachusetts, which are now foolishly sacrificed? 
These questions I then answered but imperfectly, but sta- 
tistics since received, and of which I shall hereafter give 
you, I hope, more convincing examples, have only made 
me, each year, more firm in the conviction of the affirma- 
tive of these questions, at least in all their essential ele- 
ments.12 
The writer of this article accepts the evidence 
collated by Dr. Bowditch in Massachusetts, by 
Dr. Buchanan in England, and by Dr. William 
Pepper in Pennsylvania. I accept it because it 
seems convincing, because it has not been contro- 
verted, because it is in harmony with the several 
lines of evidence which I myself have collated, and 
because I think I know why it is true; and one 
chief object of the preparation of this essay is the 
hope that the reason why may be made plain, and 
that thereby the realization by mankind of the 
grand results aimed at by Dr. Bowditch may be 
aided. 
In order to learn the reason for the truth set 
forth by Dr. Bowditch, let us first inquire what 
are the principal meteorological differences be- 
tween high and dry localities, and low and wet 
localities. 
CLIMATIC CHARACTERISTICS OF LOW AND WET, 
AND OF HIGH AND DRY LOCALITIES. 
Atmospheric Pressure.—lt is at once apparent 
that between “high” and “low” localities 
there is, of course, the difference in atmospheric 
pressure ; but the difference in atmospheric pres- 
sure due to the few feet difference in elevation be- 
tween the best and the worst localities studied by 
Dr. Bowditch could not have had great influence. 
Atmospheric Humidity.—The next most notice- 
able element is the atmospheric moisture ; and 
here, in my opinion, we strike the point from 
which our friends, in times past, have almost 
uniformly diverged from the path which would 
have led them to the truth. They have assumed, 
apparently, that a wet soil always tends to make 
a moist atmosphere over that soil, and although 
this is true if we speak only of the relative hu- 
midity (which is the per cent, of saturation of 
the air with vapor of water), it is not true if we 
speak of the absolute humidity (which is the 
amount of vapor of water which the air actually 
contains). Our predecessors have uniformly con- 
sidered only the relative humidity, while, as I 
hope to show, it is mainly the absolute humidity 
that has influence in the air passages; for the 
reason that the air exhaled, having been in con- 
tact with the warm and moist surfaces in the lungs 
and air passages, leaves the body, uniformly, sum- 
mer and winter, at about the same temperature- 
near 98° F., and nearly saturated with the vapor 
of water at that temperature. According to 
Glaisher’s and Guyot’s tables, air at 98° F., sat- 
urated with vapor, contains about 18.69. grs. of 
vapor in each cubic foot of air. This being so, 
the quantity of moisture taken out of the lungs 
and air passages in excess of that inhaled de- 
pends, not upon how nearly saturated with vapor 
the air may be when it is inhaled—not upon its 
relative humidity, because if saturated at zero it 
can contain only x/2 gr. of vapor, at 320 only 2 
grs., at 70° 8 grs., etc.—but the quantity of mois- 
ture exhaled in excess of that inhaled mainly de- 
pends upon the absolute humidity of the atmos- 
phere. If air at zero, saturated with vapor, is 
inhaled, each cubic foot of it when exhaled will 
abstract from the lungs and air passages about 
18 grs. of vapor of water.13 
What are the important influences connected 
11 In Registration Report, 1857, we find that during the five years 
including 1853 to 1857, 23,280 died of consumption in Massachusetts. 
12 Med. Com. Mass. Med. Soc., Vol. vi, Part ii, 1862, pp. 88, 89. 5 
with the excessive exhalation of water from the 
air passages ? 
Atmospheric Temperature.—Before answering 
the foregoing question, however, let us fully un- 
derstand why it is that residents over a cold damp 
soil are surrounded by an atmosphere which is cold 
and dry, absolutely, and which takes out of the 
lungs and air passages larger quantities of mois- 
ture than does air over a warm and dry soil. The 
main reason is that the atmosphere over low and 
wet soil is nearly always cold, as will presently be 
made apparent. And, as already pointed out, cold 
air is always, necessarily, dry air, so far as relates 
to the absolute quantity of moisture; although, 
because its capacity to hold moisture is slight, and 
because it has usually been cooled from a higher 
temperature, in which condition it held more va- 
por, cold air is frequently saturated with moisture 
—its relative humidity is great, but its absolute hu- 
midity is small. On the other hand, the atmos- 
phere over high and dry localities is generally 
warmer, especially when the air is still (as it usu- 
ally is at night), because then the cold air, being 
heavier than warm air, settles down into the val- 
leys, and flows along water-courses, while the 
lighter warm air rises and remains on a higher 
plane. The sensations of any ordinarily sensitive 
person are sufficiently acute to detect the cellar- 
like atmosphere of the valleys and water-courses, 
on still evenings, when one goes down into them 
from the higher levels; and the sudden transition 
from such coolness to noticeable warmth is often 
very apparent to one who ascends directly from 
the low levels to a hill top. 
quently protected from winds, yet, as soon as the 
sunshine is withdrawn, the general law that warm 
air is lighter than cold air results in there being 
generally a lake of cold air in all basin-shaped lo- 
calities, in there being streams of cold air flowing 
down15 water-courses, and, generally, in the accu- 
mulation of cold air over every locality which is 
sufficiently basin-shaped that it retains water in 
or upon the soil. This is one reason why a low, 
wet place is generally cold. Another reason is 
that the evaporation of water produces cold, 
therefore, whenever the atmosphere is not fully 
saturated with vapor of water, a wet locality is 
for this reason colder than a dry one. This is 
one reason why underdraining a soil makes it 
warmer. 
Frosts in Low, Wet Localities.—The fact that 
low, wet localities are generally cold is of such 
importance that I do not wish to slur it over, but 
to present sufficient evidence to make it conclu- 
sive. One line of evidence is that of tfle effect 
on tender vegetation. The fact that a “killing 
frost” occurs on low, wet places frequently when 
the uplands escape, is well known. It is also 
well known that, in districts where peach trees 
are grown, peach orchards on the hills frequently 
escape when those on the low lands are killed by 
the cold. 
Thermometric Observations, on Low Lands.— 
Experiments made a few years ago by Prof. R. C. 
Kedzie, at the Michigan Agricultural College, 
proved that self-registering thermometers exposed 
on the high ground registered a high*er tempera- 
ture, by several degrees, than those exposed on 
adjacent low grounds; and that the cold air ap- 
parently flowed down the natural water-course 
through the grounds. Comparative observations 
made by Mr. W. C. Haines, at Tansing, Mich., 
prove that in a valley, along the bottom of which 
runs a small stream, a self registering minimum 
thermometer (which had been compared with a 
standard instrument), generally shows the mini- 
mum temperature, even in winter months, to be 
lower than it is on the high ground in the State 
Capitol Square, in the same city, the difference in 
the elevation being only about 25 feet. 
The Atmosphere at Low Levels is Coldest at 
Night.—The greater cold at low levels is most 
frequently at night; and it is worthy of note that 
it is at a time when artificial heat is not usually em- 
ployed; and, although one may be warmly covered 
in bed, no method has been in very general use 
for the warming of the air inhaled under such cir- 
cumstances, so that the lungs and air passages are 
more influenced by cold nights than by cold days.10 
Observations made for the Royal Meteorological 
Society of Rondon, England,17 at Boston, Rincoln- 
In speaking of a house in which a case of con- 
sumption originated, Dr. Bowditch described the 
locality as follows: 
On each side of this valley arise high and sandy hills. 
With each evening sunset, a flood of cold moisture, al- 
most if not quite imperceptible to eyesight, but quite 
palpable to the sensitive skin of the traveler, settles in 
between the hills and gradually envelops this devoted 
house. I have often passed the spot late at night. At 
times the moon shone clearly on the immediately adja- 
cent ridges, but as I descended from them and passed the 
house, the rays were obscured, and a chilly feeling came 
over me, as if taking a cold bath.14 
While the sun shines, the valleys are frequent- 
ly warm, and the valleys and low levels are fre- 
A COLD VALLEY, 
!S If the wind is up stream, the flow of cold air may be up stream; 
but see results of Prof. Kedzie’s experiments mentioned further on, 
under the heading: “ Thermometric Observations on Tow Lands.” 
13 If air at zero is warmed without being supplied with mois- 
ture, and then inhaled, its drying effects on the air passages will, of 
course, be the same as if breathed at the low temperature. 
16 The curve for ozone at night in Michigan is almost precisely 
the same as the curve representing sickness from pneumonia. 
“ Med. Com. Mass. Med. Soc., 1862, p. 93. 
!7 Quar. Jour. Royal Met. Soc., October, 1887, p. 275. 6 
shire, 4 feet from the ground, and at 170, and at 
260 feet from the ground in the church tower, and 
which the Secretary of the Society says are “su- 
perior to any observations heretofore made, ’ ’ show 
that— 
I believe that all towns, parts of towns, houses even 
that rest on damp, cold soils, are by that very fact liable 
to the prevalence of consumption. I believe that similar 
locations near wet meadows, rivers, marshes, etc., though 
less subject to.the law, are nevertheless, in a lesser degree, 
promoters of consumption in the families resident there- 
upon. Even hills, with clayey subsoil retaining moisture, 
though not absolutely evil, are less good than a perfectly 
dry, porous soil, removed from any moisture.23 
Again, in speaking of choosing a site for a 
dwelling-house, Dr. Bowditch says: 
It should be in a portion of the township which is nei- 
ther so high as to be exposed to violent gusts of weather, 
nor so low that moisture will collect around it. Let it be 
on the side of a hill, or plain, open to the south, and, if 
possible, defended from the north and east, on a dry, por- 
ous soil, through which water freely percolates,and which, 
even after a rain, retains little moisture.24 
SUMMARY : ELEMENTS OF CLIMATE CHARACTER- 
IZING LOW, WET LOCALITIES. 
Perhaps this part of the subject has now re- 
ceived sufficient attention to have established the 
points which it seems important should be under- 
stood, namely : 
1. That the atmosphere over low and wet local- 
ities is cold, especially nights when, because of 
there frequently being no fires, the lungs and air 
passages are in most danger of injury, by the in- 
halation of cold air. 
2. That the atmosphere in such localities is, 
more frequently than at higher levels, saturated 
with vapor of water, as shown by psychrometric 
observations, and also by the presence of fogs, 
etc., and, what is most important— 
3. That, because the capacity of cold air to 
contain vapor of water is very small, the absolute 
quantity of water contained in the atmosphere in 
low, wet and cold localities is very small—the at- 
mosphere there is cold and dry, absolutely. 
EFFECTS ON LUNGS AND AIR-PASSAGES OF IN- 
HALING ATMOSPHERE OF LOW LEVELS. 
Therefore, when such air as is usual on low 
levels is taken into the air-passages and lungs, 
containing, as it does, only a very few grains ot 
vapor (air at zero containing at most only half a 
grain to each cubic foot), and is exhaled saturated 
with moisture at about 98° F. (each cubic foot of 
air then containing 18.69 grains of water), an ex- 
cessive quantity of moisture is abstracted from 
the lungs and air-passages and an excessive quan- 
tity of the non-volatile salts of the blood (which 
pass into the air-cells from the blood with the 
fluid which normally keeps the air-cells moist), 
an excessive quantity of these salts is left in the 
air-cells and on the mucous lining of the air-pas- 
sages. This is not stated on hypothesis alone, 
although this conclusion was reached a priori 
from causes known ; but it has since been proved 
to be true by reliable and sufficient statistics of 
sickness and of coincident meteorological condi- 
tions, and by chemical analyses of the lungs and 
The minimum temperature at 4 feet is generally colder 
than at 170 feet, except in winter months, when the latter 
is generally colder than the former. . . . The mean tem- 
perature at 4 feet, during the day hours, is always in ex- 
cess of that of 260 feet, the difference during the summer 
months amounting to about 4° at the warmest part of the 
day. As night conies on the difference becomes less A 
The general results therefore show that the diurnal 
range of temperature is much less at the top of the tower 
and on the belfry than at 4 feet above the ground 
In foggy weather the temperature at the top of the 
tower is always warmer than at 4 feet, the upper part of 
the tower being generally free from fog.19 
Fogs over Low Lands.—As illustrating the fact 
that fogs are most frequent over low, wet and cold 
levels, the remarks by the Secretary of the Royal 
Meteorological Society are applicable. He says : 
“The object of the Council in transferring the in- 
struments to Lincoln was to obtain results from a 
differently situated place. The base of Boston 
Church was only a few feet above sea level, and 
the country round was very flat, while Lincoln 
Cathedral was situated on a hill and was thus free 
from the ground fogs which so frequently occurred 
at Boston.™ 
It is proper to state that Dr. Bowditch has said: 
While claiming dampness of the soil as one of the prime 
causes of consumption in New England, Ido not assert 
that it is the sole cause, or that the combination of change- 
ableness and coldness zuith moisture, may not be vastly 
more fatal than moisture alone A 
Hillsides are Warmer than Low Levels.—It will 
be seen by the careful student that Dr. Buchanan 
carried the investigation, or at least his exact 
summarizing, further than Dr. Bowditch did; 
and, although he has not taught us what there is 
about wet, low-lying soils that causes phthisis, he 
has supplied us with one very important general- 
ization, namely : “There is less phthisis among 
populations living on sloping impervious soils 
than among populations living on fiat impervious 
soils.25 In the light of what has been pointed out 
in this essay, the reason for this now seems obvi- 
ous—the sloping impervious soil permits the cold 
overlying atmosphere to fall into the valleys be- 
low, while the flat impervious soil not only re- 
tains its own cold atmosphere but tends to send 
up the slope its warmest air, and to take in ex- 
change the coldest and heaviest atmosphere from 
the surrounding slopes. Although Dr. Bowditch 
did not in his summary clearly state the general- 
ization that sloping impervious soils are not as 
dangerous as flat impervious soils, portions of his 
address show that he held it in mind, for he says: 
is Same page—275. Italics mine. 
ipQuar. Jour, Royal Met. Soc., October, 1887, p, 277. 
22Trans. Am. Climatol. Ass’n, 1886. New York, 1887, p. 90. The 
original is in paragraph 3, on page 109. Tenth Report of the Med- 
ical Officer of the Privy Council, 1867, Rondon, 1868. 
2° Same Vol., p. 280. Italics mine. 
21 Med. Com. Mass. Med. Soc., Vol. x, No. 11, 1862, p. 90. 
23 Med. Com. Mass. Med. Soc., Vol. x, No. 11, 1862, p. 122. 
24 Page 124. 7 
sputa. Thus, by abundant statistics I have 
proved25 (and the evidence with this essay tends 
strongly to support this view) that at such times 
as pneumonia, bronchitis, influenza and other 
diseases of the throat, lungs and air-passages 
most prevail, the atmosphere is cold and dry (ab- 
solutely, although the relative humidity or per 
cent, of saturation may be great). Dr. Redten- 
bacher,26 in 1850, and since him many another 
person, has shown that during the onward prog- 
ress of pneumonia chloride of sodium, which is 
normally present, disappears from the urine. 
Lionel Smith Beale, M.8., has shown37 by analy- 
ses that the chloride of sodium which, during the 
onward progress of pneumonia, disappears from 
the urine, is found in the sputa and in the solidi- 
fied lung. It is therefore proved that just preced- 
ing the greatest prevalence of these irritative and 
exudative diseases of the lungs and air- passages 
the air inhaled is unusually dry, that the evap- 
oration of moisture and, by inference, the quantity 
of non-volatile salts left thereby, is unusually 
great; and that, as proved by analyses, the chlor- 
ides are in the sputa and in the solidified lung in 
unusual proportion; that, notwithstanding the 
action of the lymphatics, these irritant salts accu- 
mulate there. The irritation of influenza, the 
bronchial cough, the exudation on the surface of 
the air-passages and sometimes into the air-cells, 
under such circumstances does not, therefore, 
seem wonderful. It seems now to be explained. 
Yet there is still more evidence connecting the 
presence of sodium chloride in the fluids which 
moisten the air-passages with the exudation of 
the albuminous constituents of the blood serum. 
Experiments by Briicke and afterward by Hoppe28 
have proved that although albumen will not pass 
through an animal membrane toward pure water, 
it will pass to a solution of salt; and Hoppe’s ex- 
periments proved that the passage of the albumen 
is in proportion to the rapidity of the movement 
of the fluid.29 
It would seem, therefore, that the more rapid 
the evaporation of fluid from the air-passages, 
and the faster the fluid is exuded toward the un- 
usually strong solution of sodium chloride in the 
air-cells, the greater the proportion of albumen 
which will exude into the air-cells. This has an 
important bearing upon the causation of con- 
sumption, because it is quite a common belief, 
resting upon many observations, that consump- 
tion not infrequently follows exposure to taking 
“cold.” Besides, from the work of Prof. R. Koch 
and others it seems that we must conclude that 
the introduction into the body of a susceptible 
person of the bacillus tuberculosis is generally fol- 
lowed by tubercular consumption. Therefore, as 
an albuminous exudate on an irritated or inflamed 
surface in the air-passages, maintained at the 
temperature of the human body, supplies a “cul- 
ture fluid” and temperature conditions which are 
well known to be favorable to the reproduction 
of the bacillus tuberculosis, it follows that exposure 
to the inhalation of those bacilli at such times as 
such an exudate is present in the air-passages 
must lead to a larger than the average proportion 
of instances in which such bacilli are enabled to 
gain a successful lodgment in the air-passages. 
And since it has been proved that inoculation 
with the bacillus tuberculosis in other parts of the 
body is not followed by tuberculosis 
of the lungs, it seems to follow that the bacilli 
are caused to exude into the air-passages (brought 
there from tuberculous foci in other parts of the 
body); and it would seem that they would be 
most likely to be exuded, and, if exuded, to main- 
tain a lodgment there at such times as exudation 
into the air-cells or air-passages is greatest. 
Therefore, consumption of the lungs should be 
contracted most readily at such times as croup, 
influenza, bronchitis and pneumonia occur. Let 
us examine the evidence of our vital statistics, in 
order to ascertain whether or not this hypothesis 
is in accordance with the facts. 
DO IRRITATIVE, EXUDATIVE DISEASES OF THE 
AIR-PASSAGES AND DUNGS ACCOMPANY OR 
PRECEDE CONSUMPTION ? 
At the outset we are met with the difficulty 
that in most States and countries no sufficient 
statistics of sickness are recorded ; but inasmuch 
as the same course of reasoning, as to the favor- 
ing of the reproduction of the bacilli in the lungs 
and air-passages by the occurrence of a saline and 
albuminous exudate, will apply to the later stages 
of consumption as well as to the first, it follows 
that the deaths also from consumption should be 
most frequent following the occurrence of those 
conditions which cause the exudative diseases of 
the air-passages. 
For the purpose of answering the above ques- 
tion, and to supply the evidence on which this 
essay is mainly based, twenty-four tables and 
twenty-four diagrams, accurately drawn to scale 
and graphically exhibiting the essential facts con- 
tained in the tables, are submitted herewith. The 
first seven tables and diagrams show the relations 
which the deaths reported from consumption and 
from each of several diseases in Massachusetts 
sustain to those from each of the other diseases 
and to the atmospheric temperature. And since 
the absolute humidity of the atmosphere is so 
greatly controlled by the temperature, and the 
curve for absolute humidity in this part of the 
world, as shown by a comparison of it in diagram 
No. 2 with the curve for temperature in diagram 
No. i, is almost the same as the curve for tern- 
z5 Proceedings Mich. State Board of Health, Oct., 1886, pp. 7-11 ; 
Trans. Am. Clixnat. Assoc., May, 1886, New York, 1887, pp. 226-233; 
Mich, State Board of Health Report, 1886, pp. 246-324; 1887, pp. 197- 
211 ; 1888, pp. 143-169. 
26 Zeitschrift der K. K. Geselschaft der Aertze zu Wien, Aug., 1850. 
27 Trans. Medico-Chirurg, Soc., Vol. xxxv, 1852. 
28 Virchow’s Archiv, Vol. q, 1856, pp. 245-268. 
29 Virchow’s Archiv, Vol. 9, 1856, pp. 265-267. 8 
perature, the several diagrams also show, to 
whomsoever will hold these facts in mind, the re- 
lations of the deaths reported from the several 
diseases to the absolute humidity of the atmos- 
phere. For one disease, croup, diagrams i and 
2 illustrate these relations fully. 
In studying the relations of the several diseases 
it should be borne in mind that the average dura- 
tion is not the same for all; therefore, it cannot be 
expected that there would be exact uniformity— 
that the time between the exposure to the cause 
and the fatal result shall be the same for all dis- 
eases. Bearing this in mind, an examination of 
the several diagrams shows that these diseases 
sustain such relations to the temperature and ab- 
solute humidity of the atmosphere as to indicate 
that these conditions are causal. 
A very noticeable departure from quantitative 
relations—the same in different parts of the year 
—is to be seen in the diagrams relative to croup, 
consumption and diphtheria, and is slightly ap- 
parent in the curves relating to small-pox. It is 
a lower curve than proportional in those months 
when the atmosphere is becoming more warm and 
moist, and a higher curve in those months when 
the atmosphere is constantly becoming cold and 
dry. It is as if those who were injured by a very 
cold dry air do not die if warmer weather ensues, 
and those taken sick in comparatively warm 
weather die in unusual proportion in the autumn 
months, as the weather constantly becomes colder 
and drier. This is strongly marked in diagram 
No. 3, relating to consumption. In that diagram, 
considering the fact of the general relations of the 
two curves, there are also hints that possibly con- 
sumptives guard against exposures more success 
fully in the coldest months. It is quite possible, 
and I think probable, that these statistics of 
deaths from consumption in Massachusetts in re- 
cent years are modified by the great numbers of 
consumptives and persons with susceptible lungs 
who leave that State in the autumn and do not 
return from their southern trip until spring. 
This becomes more apparent when one compares 
diagram No. 3 with diagrams exhibiting the 
curves for consumption in some other parts of the 
world, although the same principles seem to hold, 
to some extent, in most cases; but in the dia- 
grams of deaths and of sickness from consumption 
in the United States armies during the war of the 
rebellion it is much less apparent than it is in the 
diagram (No. 3) relative to deaths in Massachu- 
setts. 
Turning now to the more extensive mortality 
statistics in London, England, it is seen, by a 
glance at the several diagrams (diagrams 10, 12, 
20, 22), that the curves for the diseases of the 
lungs and air-passages follow the curves for atmos- 
pheric temperature with such uniformity as to 
indicate quantitative causal relations. That the 
curve for consumption in Loudon (diagram No. 
io) does not fall so noticeably as it does in Mas- 
sachusetts in the winter months, may be, in part, 
due to the fact that the statistics extend back to 
a time when journeys southward in the autumn 
were not so much the custom as at present. 
The diagrams show that in London the deaths 
from consumption do follow, from one to three 
months later, the deaths from bronchitis and 
pneumonia. 
Tables and diagrams 8, 9 and 23 exhibit the 
facts respecting the rise and fall of the sickness 
from pneumonia and consumption, and the deaths 
from consumption in the United States armies 
during the war of the rebellion. The statistics 
are quite extensive, and as they exhibit the facts 
relative to the sickness as well as the deaths, they 
are especially valuable. It will be seen that the 
sickness and the deaths from consumption do in 
general follow the sickness from pneumonia; also 
that the sickness from pneumonia follows the 
changes of atmospheric temperature with such 
closeness and regularity as to show that, directly 
or indirectly, the temperature sustains causal re- 
lations. 
That the control of diseases of the air-passages 
by atmospheric temperature is not confined to 
this country and England, but applies also to 
countries having very much warmer atmosphere, 
is proved by the table and diagram No. 14, which 
show that in India the diseases of the air-passages 
(not including consumption) are controlled by the 
temperature. 
Finally there are submitted herewith tables and 
diagrams (Nos. 15 to 21 inclusive) proving that 
in Michigan (in which State valuable statistics of 
sickness are collected) the sickness from nearly 
every one of the entire class of diseases of the air- 
passages and lungs is controlled by the atmos- 
pheric temperature, and that the sickness from 
consumption follows, in general, the law which 
has herein been pointed out. 
In all the countries, States, cities and armies 
concerning which I have thus far studied the sta- 
tistics relating to this subject, the same law seems 
to hold : a very considerable proportion of the 
sickness and the deaths from consumption follow, 
or sustain such relations to, the irritative and 
exudative diseases of the air-passages and lungs 
as to prove a necessary or causal relation; and 
these other diseases of the air-passages and lungs 
are quantitatively related to the temperature and 
absolute humidity of the atmosphere, proving 
that, directly or indirectly, they are controlled by 
these atmospheric conditions. I have pointed 
out how, in my opinion, this occurs, namely, in- 
directly through the absolute humidity of the at- 
mosphere, which, so far as its maximum is con- 
cerned, is absolutely controlled by the tempera- 
ture, cold air being always necessarily dry air. 
Nor is this all of the evidence. As elsewhere 
pointed out, it is proved that the deaths from 9 
small-pox follow the same law, as should, theo- 
retically, be the case, because the same remarks, 
as to the saline and albuminous exudate in the 
air-passages at the temperature of the body being 
the best possible “culture fluid” and temperature 
conditions for the specific cause of consumption, 
apply as well to the specific cause of small-pox. 
Therefore, the accompanying tables and diagrams 
(4 and 22) on this subject are submitted in this 
connection. 
The fact that small-pox and other diseases 
known to be communicable and to enter the body 
by way of the air-passages are in great part con- 
trolled by the atmospheric temperature, as is 
shown by diagrams 4, 5, 7, 22 and 24, is, by it- 
self, strong presumptive evidence that such a dis- 
ease as consumption, a disease in which also the 
specific cause is believed frequently to enter the 
body by way of the air-passages, will be controlled 
by similar atmospheric conditions. 
A comparison of diagrams 10 and 22 shows 
that the curves for deaths from small-pox and 
consumption in London, Lngland, are almost 
identical. This must have come about through 
the inhalation of cold air, which led to irritations 
and exudations in the air-passages and lungs, 
and thus favored the contraction of both of these 
diseases ; but, inasmuch as otherwise we would 
admit that the average duration (of the periods 
of incubation and of the diseases) was the same 
in both diseases, it would seem to be proved that 
the progress of the later stages of consumption 
also is influenced by the irritation and exudations 
caused by the inhalation of cold air. How this 
is possible has already been explained. 
other affections, such as Bright’s disease or carci- 
noma.31 
Dr. K. L,. Trudeau, of Saranac Lake, N. Y., 
has said : 
Vibert recently, while making 131 autopsies at the Paris 
morgue on persons who had come to their death by vio- 
lence while apparently in good health, noted in twenty- 
five—that is, in more than nineteen per cent.—the pres- 
ence of some slight tubercular lesion. In seventeen of 
the twenty-five a few calcarious and fibrous nodules re- 
mained as the only evidence of an unsuspected and ar- 
rested tubercular process, but in none were the patho- 
logical changes in the lungs extensive. Recovery often 
follows the operations now undertaken for tubercular 
peritonitis, though it is evident that all the infectious 
material cannot be removed. 
The records of the autopsies made by Vibert, Council- 
man and others, as well as the evidence offered by the 
present research [Dr. Trudeau’s experiments on the in- 
fluence of environment on consumption], furnish proof 
that the tissues themselves can, under certain conditions, 
either limit the destructive action of this microbe [bacil- 
lus tuberculosis], or even entirely rid themselves of its 
presence.32 
The experiments by Dr. Trudeau on the influ- 
ence of environment on the course -of tubercular 
disease artificially induced by the inoculation of 
animals (published in the “Transactions of the 
American Climatological Association’’ for 1887 
and 1888) have demonstrated, apparently, that 
something similar to what has been set forth by 
Drs. Bowditch and Buchanan as true of the in- 
fluence of climatic environment on mortality from 
consumption in the human species, is true rela- 
tive to animals. Rabits inoculated with the ba- 
cillus tuberculosis and kept in a cellar-like place 
on restricted diet, died of the disease in much 
greater proportion than did similar animals simi- 
larly inoculated but kept in the open air with 
abundance of food. Under such favorable con- 
ditions a large proportion of the animals recov- 
ered so far, at least, as to maintain good health, 
although the local infection was not destroyed, 
but only circumscribed. 
THK CAUSATION OF CONSUMPTION IS COMPUKX. 
It seems to be difficult for the human mind to 
grasp more than one idea at a time. Accordingly 
we find a strong tendency to assume that there is 
and can be but one cause or essential condition 
leading to consumption; but nothing is more cer- 
tain than that the forces and reactions in nature 
are complex, and to me the evidence is conclusive 
that the causation of consumption is complex. 
But, although complex, I believe the problem is 
now quite within our grasp, in all its most im- 
portant features, if we only hold fast to the truths 
we have learned of the relations of consumption 
to low, wet places, while we grasp the obverse 
idea of the favorable influences of high, dry and 
sunny places ; hold fast to this double image of 
one great truth, while we lay hold of that one 
a large; proportion of those; who have 
CONSUMPTION RECOVER. 
That there are conditions under which human 
beings recover from consumption seems to be well 
proved by many observers. Dr. H. P. Toomis, 
of New York, is recently reported to have stated 
that “in no less than 60 per cent, of all patients 
dying at Bellevue Hospital there were old tuber- 
cular changes in the lungs, the disease having 
been recovered from. ’ ’3O 
If 13 or 15 per cent, of all deaths are from con- 
sumption, and 60 per cent, of those who die of 
other diseases have had consumption, or at least 
1 ‘ tubercular changes in the lungs, ’ ’ from which 
they have recovered, it would appear that the 
specific cause gains a lodgment in 73 per cent, of 
all persons, and proves fatal in only about 13 or 
15 per cent, of all persons. This has an impor- 
tant bearing upon the view that the bacillus tuber- 
culosis is the only cause which it is worth while 
to study. A recent writer, speaking of tubercu- 
lar phthisis, said: “In the autopsies made at 
the Philadelphia Hospital it is surprising to see 
the almost universal presence of this disease, in a 
more or less active state, in patients dying from 
30 Jour. Am. Med. Assoc., May 18, 1889, p. 718. 
3i J. H. Musser, M.D., reported in the Medical and Surgical Re- 
porter, Philadelphia, Jan. 26, 1889, p. 102. 
32 Trans. Am. Clirgatolog. Assoc., 1888, pp. 93—94. 10 
which teaches us the great importance of proper 
clothing, food and all that goes to make the nour- 
ishment of the body fully equal to all demands 
upon it; hold fast to this rather complex thought 
while we grasp the great truth which Dr. Robert 
Koch has given us, that there is a specific cause 
which under favoring circumstances and conditions 
is an essential factor in the causation of consump- 
tion ; and, while holding all this in mind, I ask 
you to consider how it is that this specific cause 
usually enters the body, and the fact that just as 
the specific causes of many other diseases (as is 
proved by the statistics of sickness and deaths 
which I present to you at this time), just as they 
enter and cause the disease in proportion to the 
coldness and dryness of the atmosphere, so the 
specific cause of consumption apparently and 
probably finds lodgment in the lungs and air-pas- 
sages, other things being equal, in proportion to 
the coldness and dryness of the atmosphere ; and 
not onty this, but the danger of auto-infection 
and of death to one in whose body the disease is 
already present is increased by exposure in an at- 
mosphere unusually cold and dry, while the con- 
dition of the blood is such that saline and albu- 
minous exudates are liable to occur in the air- 
passages, 
Finally, in order to grasp the most at once, we 
need to link the facts together, realizing the fact 
that over the low wet soil there is generally a cold, 
dry atmosphere, thus making it plain that the 
facts observed and collated by Drs. Bowditch and 
Buchanan are entirely in harmony with those ob- 
served by Dr. Koch, and with the enormous num- 
bers of facts which I have tabulated, and which 
prove beyond question that there is a causal re- 
lation between the inhalation of such an atmo- 
sphere and the occurrence of all the ordinary dis- 
eases of the air-passages and of those communi- 
cable diseases which enter by way of the air-pas- 
sages, including tubercular consumption. 
indicated to have been produced by the tempera- 
ture changes shown in the diagram. Had we 
records of the temperature, and of the deaths 
from phthisis for smaller divisions of time, for 
each day, for instance, it seems to me probable 
that the fluctuations of temperature would be 
seen to have sustained a causal relation to a large 
proportion of the deaths from phthisis, even in 
the most favorable month. Unfortunately, such 
perfect records are not available. But the mate- 
rial was originally compiled by weeks, and during 
the fourth week of September the deaths were 
only 130, or 2.4 less than the average for that 
month, apparently responding to a rise of tem- 
perature which occurred eight weeks before—the 
usual difference of time between the fluctuations 
of temperature and those of the deaths. Substi- 
tuting this 130 (deaths) for the 132.4 used in the 
above calculations, gives 28,236 deaths as due to 
the weekly fluctuations of temperature, or 3,744 
more than by the mo7ithly records. If dividing 
the unit of comparison (one month) by 4 shows 
3,744 more deaths produced by the fluctuations 
of temperature, what would dividing by 30, or a 
comparison of observations by days, show? We 
do not know absolutely; but by analogy we are 
led to believe that accurate records of the temper- 
ature and of the deaths from consumption would 
show that a large proportion of the deaths from 
phthisis were quantitatively related to atmos- 
pheric temperature. 
Yet this relation would necessarily be obscured 
by the greater power possessed by some patients 
than by others to resist the inroads of consump- 
tion. For, on account of the varying duration 
of the disease, the deaths, instead of always oc- 
curring at the same interval after the exposure to 
the primary cause (cold and contagium), are scat- 
tered along according to the virulence of the con- 
tagium and the resisting power of the patient, 
thus grading down the elevations and filling up 
the depressions in the curve representing deaths 
from phthisis until it approximates a horizontal 
line showing only surface fluctuations correspond- 
ing with the temperature fluctuations. 
The fact that the diseases of the lungs and air 
passages and the communicable diseases which 
enter by way of the air passages are later than 
the exposure to cold by a time equal to the aver- 
age duration of the disease and the period of in- 
cubation, is shown by the diagrams which I pre- 
sent. Thus the maximum sickness from influenza, 
tonsillitis and croup is in the same month as the 
greatest exposure to cold, while pneumonia follows 
one month later, and, according to the most com- 
plete statistics, shown in Diagrams 10 and 22, the 
changes in the deaths from small-pox and con- 
sumption follow at a period of about two months 
after the temperature changes. 
I believe that if the average duration of con- 
sumption was as uniform as is the average dura- 
ONE RELATION OF STATISTICS OF CONSUMPTION 
TO STATISTICS OF TEMPERATURE. 
By Diagram No. 10, it may be seen that in the 
City of Dondon during thirty years the fluctua- 
tions in the number of deaths from phthisis fol- 
lowed the fluctuations of temperature, nearly as 
constantly as a shadow, rising and falling, not 
with but after the temperature changes. In the 
month of September (following the most favorable 
temperature in July) the deaths reach the lowest 
point—an average of 232.4 per week. If the tem- 
perature had continued thus favorable throughout 
the period, it is reasonable to believe that the 
deaths for each month would have remained the 
same—an average of 232,4 per week, or 6,884.8 
per year, amounting to 206,544 deaths during the 
period of thirty years. Deducting this number 
from the number of deaths which really occurred, 
231,036, leaves 24,492 as the number of deaths tion of small-pox, the proportion of the deaths 
which would be seen to be quantitatively related 
to the atmospheric temperature would be as great 
with consumption as with small-pox; and, as may 
be seen in Diagram No. 22, there were twice as 
many deaths from small-pox following the coldest 
season of the year as there were following the 
warmest season. 
preceded in time and place (and inferentially in 
the same individual, by one of these diseases), by 
the irritative and exudative diseases of the lungs 
and air-passages, such diseases as influenza, ton- 
sillitis, croup, bronchitis and pneumonia gener- 
ally preceding, in the same locality, the occur- 
rence of recognized consumption ; they are, ap- 
parently, conditions antecedent to consumption. 
7. Statistics of sickness and of deaths, collated 
with meteorological statistics (Seibert, Baker), 
prove that the irritative and exudative diseases 
of the lungs and air-passages follow uniformly and 
quantitatively, in their rise and fall, the fall and 
rise of the atmospheric temperature, indicating 
that, directly or indirectly, atmospheric tempera- 
ture is a co7itrolling cause of those diseases. 
8. The accumulation of non-volatile salts (chlor- 
ides) in the sputa and solidified lung in pneumo- 
nia (Beale), coupled with the fact of the disap- 
pearance of the chlorides from the urine during 
the onward progress of pneumonia (Redtenbach- 
er), collated with statistics of sickness, of deaths 
and of meteorological conditions, and with cer- 
tain facts in physiology (Briicke and Hoppe), 
pathology (Stokvis), and chemistry, seem to 
prove that the control which atmospheric tem- 
perature has of pneumonia (and, if of pneumo- 
monia, also its control of all those irritative and 
exudative diseases of the lungs and air-passages, 
which it does control), is not direct, but indirect 
through its well-known control of the atmospheric 
humidity, and so of the quantity of water exhaled 
from the lungs and air-passages, influencing the 
quantity of non-volatile salts which may there 
accumulate. 
9. Residence in low, wet localities tends toward 
the causation of consumption, and toward the fa- 
tality of the disease (Bowditch, Buchanan, Pep- 
per, Trudeau), because in all such localities the 
atmosphere is cold, and consequently its absolute 
humidity is small. Other concomitant conditions 
may contribute greater atmospheric pressure, 
greater daily range of pressure, greater daily 
range of temperature, more active oxidation, less 
tendency toward deoxidation than occurs under 
free exposure to sunlight, lack of sufficient nour- 
ishing food, etc. 
10. Among causes known, or believed, to be 
Predisposing to consumption, are ; heredity; tem- 
perament (certain types of auburn-haired persons 
being supposed to be especially liable to consump- 
tion) ; narrow lymph-spaces in the connective 
tissue (Forraad),33 possibly because of their more 
readily clogging up by saline, albuminous or 
fibrinous exudations ; and excess of such non- 
volatile salts as sodium chloride in the food or 
drink. 
THE CAUSATION OF CONSUMPTION—SUMMARY. 
In order that mankind shall be able to prevent 
or avoid the causes of consumption, it seems es- 
sential that its causation should be understood. 
It would seem that we are now in possession of 
sufficient knowledge of its causation so that, if 
we will but act upon that knowledge, a large 
proportion of the sickness and deaths from this 
most important of all diseases, may be prevented. 
What are the generalizations which supply the 
bases for effort for the prevention or avoidance of 
consumption ? They seem to be about as follows : 
1. Microscopic organisms called bacilli, of a 
species known as bacillus tuberculosis (Koch), ac- 
company the disease commonly known as con- 
sumption. 
2. Introduced into a susceptible organism, ba- 
cillus tuberculosis is able to reproduce, and, appar- 
ently, to cause and continue the condition known 
as consumption. 
3. These bacilli are present in the sputa of 
consumptives ; and, although outside the body at 
ordinary low temperatures they do not multiply 
by reproduction, they are not destroyed by dry- 
ing, and, consequently, in apartments occupied 
by consumptives who do not take care to so dis- 
pose of the sputa that they shall not become a 
part of the dust of the room, the dust may con- 
tain the bacilli, or their spores. Because so large 
a proportion of people have consumption, the 
dust of halls and public places where sputa reach 
the floors and may become a part of the dust of 
the room, such dust may contain these bacilli, 
which are believed to be the specific cause of the 
disease. 
4. The bacilli of consumption are introduced 
into the body in various ways ; but, apparently, 
most frequently by way of the air-passages. (The 
order of the invasion of the lobes of the lungs is 
tolerably well understood.) 
5. Statistics of sickness, and of deaths, collated 
with meteorological statistics, seem to prove that 
the consumptive processes go on most actively 
after times of low atmospheric temperature, and 
least actively after times of high atmospheric 
temperature. It would seem that atmospheric 
temperature is, directly or indirectly, a co?itrolling 
cause of consumption. 
6. Statistics of sickness and of death from con- 
sumption, collated with statistics of sickness and 
deaths from other diseases, prove that, in the long 
average, consumption is somewhat uniformly 
THE PREVENTION OF CONSUMPTION. 
We come now to the most important utilitarian 
33 Jour, of Am. Med. Ass’n, Vol. 2, p. T4B. question connected with this subject,—What can 
be done to lessen the ravages of this most de- 
structive disease ? 
It is gratifying to be able to say that, if we 
accept the evidence collected in this essay, much 
can be done ; and that there is promise of the 
prevention of a very large proportion of the sick- 
ness and of the deaths from consumption, through 
the adoption of measures which are not difficult, 
yet which require, for their most speedy and com- 
plete accomplishment, such an amount of coop- 
eration by all classes of people as can only be se- 
cured through the faithful labors of intelligent 
boards of health, or of some agency for the thor- 
ough dissemination of the truth respecting this 
disease and the means for its avoidance, restric- 
tion, prevention, and climatic and other treat- 
ment. It is still true as written in the Bible— 
‘ ‘ My people are destroyed for lack of knowl- 
edge.”34 When once the people know, fully, how 
and why consumption is caused, they will find 
and adopt rational methods of protection from 
that disease. 
more liberal supply of fresh air to all occupied 
apartments, especially public rooms, would lessen 
the danger of inhaling air which has already 
been breathed, and also of microorganisms, etc. 
So long as the specific cause of consumption is so 
'widespread, lives may probably be saved by the 
use of respirators by those who sweep and dust 
rooms which consumptives have occupied. 
3. Generalizations Nos. 5 and 7 make it im- 
portant that consumptives, and persons suscepti- 
ble to consumption, should especially guard 
against the inhalation of cold air. It enforces 
the importance of having such persons spend the 
winters in a climate warmer than that to which 
they have been accustomed. 
4. Generalization No. 6, in connection with 
Nos. 1, 2, 3 and 4, teaches us that it is important 
that every person suffering from one of the irri- 
tative or exudative diseases of the lungs or air- 
passages, should be especially protected from the 
inhalation of the bacillus tuberculosis. 
5. Generalization No. 8 enforces the importance 
of supplying moisture to all air which requires to 
be warmed, in hospitals, houses, public buildings, 
and wherever the temperature of the air can be 
controlled. 
6. Generalizations Nos. 8 and 10 teach us that 
it may be of very great importance to see that our 
food and drink, especially in winter, shall not 
contain an excess of chloride of sodium or other 
non-volatile salt liable to be exuded into the air- 
cells or air-passages, and left there by unusual 
evaporation of vapor through the inhalation of 
cold air, which is necessarily dry, or of air which 
has been warmed without the addition of moisture. 
6. Generalization No. 9 has been previously 
commented on, and some of the advice based upon 
it by Dr. Bowditch has been quoted. But his 
results have been so well upheld by Drs. Buchan- 
an and Pepper, and by the experiments of Dr. 
Trudeau, that since we now think we know the 
reason why residence over low, wet soil endangers 
health and life from consumption, there should 
be no hesitation in acting in accordance with the 
laws laid down by Dr. Bowditch, relative to the 
avoidance of residence over low, wet soil, and in 
any cellar-like place. 
8. In addition to what is generally known for 
the prevention of small-pox, diphtheria and scar- 
let fever, the facts incidentally set forth in this 
essay teach why it is that the inhalation of cold, 
dry air is an important factor in the causation Of 
those diseases, and why it is even more important 
in winter than in summer to guard people from 
them. 
9. Finally, there is given herein evidence as to 
the causation of a large class of ordinary diseases 
(of the lungs and air-passages), which should lead 
to the prevention of a very considerable propor- 
tion of the sickness and deaths therefrom. 
That there shall be a very thorough dissemi- 
preventive measures. 
1. Having in mind the foregoing generaliza- 
tions, numbered 1, 2, 3, 4, relative to the sup- 
posed specific cause of consumption, it would seem 
to be practicable to so enforce, upon the minds of 
the people generally, the importance of the de- 
struction or the disinfection of all sputa from 
consumptives, that the present very general dis- 
tribution35 of those microorganisms shall be very 
greatly lessened. 
The consumptive might carry small pieces of 
cloth, each just large enough to properly receive 
one sputum, and paper envelopes or wrappers in 
which the cloth may be put as soon as once used, 
and with its envelope burned on the first oppor- 
tunity. 
2. What has been said about the destruction or 
disinfection of the sputa of consumptives should 
apply also to the dejecta ; because it has been 
shown (by Friedlander36) that the bacilli are to 
be found in the urine of persons with tubercular 
disease of the urinary organs, and in the faeces of 
those with tubercular disease of the bowels, and 
they may be in the faeces of those who swallow 
sputa containing the bacilli, that is, possibly, of 
any consumptive. 
Through better systems of ventilation, much 
may be done for the lessening the number of mi- 
croorganisms inhaled with the dust of floors, car- 
pets, etc.; especially by having the foul air exits 
at the floor-level, so that the general motion of 
the foul air shall be downwards, and not upwards 
into the nostrils of the inmates of the room. A 
34 Hosea, Chapter IV, verse 6. 
35 Dr. James E. Reeves, ex-Pres. of the Am. Public Health As- 
sociation, demonstrated the presence of innumerable tubercle ba- 
cilli in a sputum on the sidewalk, near the post office in Wheeling, 
W. Va. They are probably to be found on the sidewalk in every 
city. 
36 Manual of Microscopical Technology, pp. 219, 236, 237. nation of the truth, or at least of the nearest ap- 
proach to the truth that is now known, respect- 
ing these subjects which are of vital consequence 
to every man, woman and child, and that, through 
the attention to such subjects which shall result 
from such thorough dissemination, many valua- 
ble lives may be saved, and much suffering and 
sorrow may be prevented, is the earnest wish of 
the author of this essay. 
Tablet.—Exhibiting by months reduced to uniform length—3o days each—the number of deaths from croup in Massachusetts dur- 
ing 23 years, 1863-85, in comparison with the average atmospheric temperature for 48 yearsl (1790—1870) at Cambridge, Mass. Deaths 
computed from the 44th Registration Report of Massachusetts, 1886; and the temperature is taken from the Smithsonian tables, 
“Distribution and Variations of Atmospheric Temperature,” 1876, p. 40. 
CROUP AND TEMPERATURE IN MASSACHUSETTS. 
j Jan. 
Feb. 
Mar. 1 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Deaths.2 
Av. temperature. 
1,469 
25-2= 
1,290 
26.28 
1,181 1 
34-39 1 
1,023 
44.40 
774 
56.01 
559 
66.74 
c« 00 
M 
435 
69.82 
729 
61.89 
1,239 
50.18 
1,6493 
39.28 
1,631 
29-34 
1 The series is stated as follows: “ Begins Jan. 1790; ends Dec. 1870; extent, 48 years and 6 months.” Some of the years between 
1790 and 1870 were omitted. This series is used because it is the longest available, and, therefore, most likely to give the correct 
11 normal” curve. That it does supply a correct “ norm,” and that, in table 2 and diagram No. 2, the normal curve representing 
absolute humidity is shown, is made evident by a comparison of the curve for temperature in diagram No. 1 with the curve for ab- 
solute humidity in diagram No. 2, noting how closely the two curves resemble each other, and considering how completely the 
absolute humidity of the atmosphere is controlled by the atmospheric temperature. The two curves are so nearly alike that it 
has been thought not necessary to make any more diagrams exhibiting the absolute humidity in Massachusetts, but to let the 
curve representing the temperature—the controlling condition—stand also as representing the absolute humidity. 
2 Total deaths from croup in the 23 years, distributed by months. 
3 To the author of this essay it seems probable that some proportion of the deaths recorded as from croup were from diphtheritic 
croup, and also that some part of the rise in the autumn, after the opening of the schools, may be due to the spreading of that 
communicable disease. 
CROUP AND ABSOLUTE HUMIDITY IN MASSACHUSETTS. 
Table 2.—Exhibiting by mouths reduced to uniform length—3o days each—the number of deaths from croup in Massachusetts dur- 
ing 23 years, 1863-85, in comparison with the average absolute humidity of the atmosphere at Boston during 17 years, 1870-86, com- 
puted from the tables on relative humidity and temperature, in the Report of the Chief Signal Officer, U. S. A., for 1886.4 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
August. 
Sept. 
October. 
Nov. 
Dec. 
Deathss 
1,469 
1,290 
1,181 
1,023 
774 
559 
427 
435 
729 
1,239 
1,649 
1.631 
Abs. Humidity. . 
i-39 
i-45 
1.87 
2.32 
3-37 
4.81 
5-78 
5.66 
4-56 
3-19 
2.19 
i-59 
4 That this supplies satisfactory data concerning the absolute humidity of the atmosphere in that vicinity is made probable by 
the steadiness of the curve, as may be seen in diagram No. 2, and especially by a comparison of that curve with the one represent- 
ing the atmospheric temperature at Cambridge, Mass., in diagram No. 1. 
5 Total deaths from croup in the 23 years, distributed by months. 
CONSUMPTION AND TEMPERATURE IN MASSACHUSETTS. 
Table 3.—Exhibiting by months reduced to uniform length—3o days each—the number of deaths from consumption in Massachusetts 
during 23 years, 1863-85, in comparison with the average atmospheric temperature for 48s years (1790—1870) at Cambridge, Mass. 
(Deaths computed from the 44th Registration Report of Mass., 1886; and the temperature is taken from the Smithsonian tables, 
“ Distribution and Variations of Atmospheric Temperature, 1876,” p. 40.) 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
August. 
Sept. 
October. 
Nov. 
Dec. 
Deaths? 
Av. Temperature. 
9,888 
25-25 
10,261 
26.28 
10,723 
34-39 
10,658 
44.40 
10,390 
56.01 
9,223 
66.74 
9,273 
71.86 
9.773 
69.82 
9,875 
61.89 
9,606 
50.18 
9,590 
39.28 
9,607 
29-34 
6 The series is stated as follows; “Begins Jan,, 1790; ends Dec., 1870; extent, 48 years and 6 months.” Some of the years be- 
tween 1790 and 1870 were omitted. This series is used because it is the longest available, and, therefore, most likely to give the 
correct normal curve. 
7 Total deaths from consumption in the 23 years, distributed by months. 
Table 4—Exhibiting by months reduced to uniform length—3o days each—the number of deaths from small-pox in Massachu- 
setts during 23 years, 1863-85, in comparison with the average atmospheric temperature for 48 yearsB (1790-1870) at Cambridge, Mass. 
Deaths computed from the 44th Registration Report of Massachusetts, 1886; and the temperature is taken from the Smithsonian 
Tables, “Distribution and Variations of Atmospheric Temperature,” 1876, p. 40. 
SMALL-POX AND TEMPERATURE IN MASSACHUSETTS. 
Jan. 
Feb. 
March. 
April. 
May. 
June. 
July. 
August. 
Sept. 
October. 
Nov. 
Dec. 
Deaths? 
Av. Temperature. 
458 
25-25 
3H 
26.28 
269 
34-39 
270 
4440 
295 
56.01 
202 
66.74 
177 
71.86 
Ill 
69.82 
152 
61.89 
214 
50.18 
3D 
39.28 
489 
29-34 
8 The series is stated as follows : “ Begins Jan., 1790, ends Dec., 1870; extent, 48 years and 6 months.” Some of the years between 
1790 and 1870 were omitted. This series is used because it is the longest available, and therefore most likely to give the cor- 
rect normal curve. 
9 Total deaths from small pox in 23 years, distributed by months. DIPHTHERIA AND TEMPERATURE IN MASSACHUSETTS. 
Table 5.—Inhibiting' by months reduced to uniform length—3o days each—the number of deaths from diphtheria in Massachusetts 
during 23 years, 1863-85, in comparison with the average atmospheric temperature for 48 yearslo (1790-1870), at Cambridge, Mass. 
(Deaths computed from the 44th Registration Report of Mass., 1886; and the temperature is taken from the Smithsonian Tables, 
“ Distribution, and Variations of Atmospheric Temperature, 1876,” p. 40.) 
Jan. 
Feb, 
March. 
April. 
May. 
June. 
July- 
August. 
Sept. 
October. 
Nov. 
Dec, 
Deaths11 
2,527 
2,174 
1,825 
1,736 
1.643 
1.588 
1,365 
1,284 
1,818 
2,598 
2,712 
2,687 
Av. Temperature. 
25-25 
26-28 
34-39 
44,40 
56.01 
66.74 
71.86 
69.82 
61.89 
50.18 
39.28 
29-34 
xo The series is stated as follows : “Begins Jan., 1790; ends Dec., 1870 ; extent, 48 years and 6 months.” Some of the years be 
tween 1790 and 1870 were omitted. This series is used because it is the longest available, and therefore most likely to give the cor- 
rect normal curve. 
Note.—The opening of Schools in the autumn may have to do with the increase culminating in November. 
11 Total deaths from diphtheria, in 23 years, distributed by months. 
PNEUMONIA AND TEMPERATURE IN MASSACHUSETTS. 
Table 6.—Exhibiting by months reduced to uniform length—3o days each—the number of deaths from pneumonia in Massachu- 
setts during 23 years, 1863-85, in comparison with the average atmospheric teynperature for 48 years12 (1790-1870), at Cambridge, Mass. 
(Deaths computed from the 44th Registration Reports of Mass., 1886 ; and the temperature is taken from the Smithsonian Tables, 
“ Distribution, and Variations of Atmospheric Temperature, 1876,” p. 40.) 
Jan. 
Feb. 
March. 
April. 
May. 
June. 
July. 
August. 
Sept. 
October. 
Nov. 
Dec. 
6,048 
6,791 
7,042 
6,508 
4,967 
2,776 
1,828 
I.5I4 
1,913 
2,767 
4,125 
5,221 
Av. Temperature. 
25-25 
26.28 
34-39 
44.40 
56.01 
66.74 
71.86 
69.82 
6r.8g 
50.18 
39.28 
29-34 
i 2 The series is stated as follows; “ Begins Jan., 1790; ends Dec., 1870; extent, 48 years and 6 months.” Some of the years be- 
tween 1790 and 1870 are omitted. This series is used because it is the longest available, and therefore most likely to give the cor- 
rect normal curve. 
i 3 Total deaths from pneumonia, in the 23 years, distributed by months. 
SCAREATINA AND TEMPERATURE IN MASSACHUSETTS. 
Table 7.—Exhibiting by months reduced to uniform length—3o days each—the number of deaths from scarlatina in Massachu- 
setts during 23 years, 1863-85, in comparison with the average atmospheric teynperature for 48 yearsD (1790-1870), at Cambridge, Mass. 
(Deaths computed from the 44th Registration Report of Mass., 1866; and the temperature is taken from the Smithsonian Tables, 
“ Distribution, and Variations of Atmospheric Temperature, 1876,” p. 40.) 
Jau. 
Feb. 
March. 
April. 
May. 
June. 
J«iy- 
August. 
Sept. 
October. 
Nov. 
Dec. 
Av. Temperature. 
2,340 
25-25 
2,253 
26.28 
2,313 
34-39 , 
2,209 
4440 
2,017 
56.01 
1,655 
66.74 
1,224 
71.86 
1,026 
69.82 
953 
61.89 
1,247 
50.18 
1.704 
39-28 
1,964 
29-34 
14 The series is stated as follows : “Begins Jan., 1790; ends Dec., 1870; extent, 48 years and 6 months.” Some of the years be- 
tween 1790 and 1870 were omitted. This series is used because it is the longest available, and therefore most likely to give the cor- 
rect normal curve. 
15 Total deaths from Scarlatina, in 23 years, distributed by months. 
Table B.—Exhibiting by months for a series of years the average atmospheric temperature at six stations representing approxi- 
mately the latitude and longitude of the Aggregate forces of the Armies of the United States in the war of the Rebellion, in compar- 
ison with the average number of cases of sickness from pneumonia per 10,000 (“ mean strength”) of those forces, by months (of uni- 
form length) during the four years, 1862-65. 
TEMPERATURE AND SICKNESS FROM PNPJUMONIA IN U. S. ARMIES. 
Jan. 
Feb. 
March. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Cases per 1,000 of Mean Strength .... 
38.1 
41.7 
38.1 
28.4 
15-9 
10.5 
8.1 
7.2 
7-7 
14.1 
23.8 
2Q.I 
Average Atmospheric Temperature. . . 
36 
38 
45 
54 
66 
74 
78 
76 
69 
56 
46 
38 
Table 9.—Exhibiting, by months reduced to uniform length—3o days each—for the four years, 1862 65, the average number of cases 
of consumption per 10,000 soldiers (“mean strength”) of the white troops of the U. S. Army in the war of the Rebellion, in compari- 
son with the average atmospheric temperature at six stations representing approximately the latitude and longitude of the aggregate 
forces of the Armies of the United States. 
SICKNESS FROM CONSUMPTION IN WHITE TROOPS, U. S. ARMY, AND TEMPERATURE. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Aver, cases per 10,000 of Mean Strength, 
Average Temperature at Six Stations. . 
5-63 
3i 
5-95 
38 
5-92 
45 
5.08 
54 
4-33 
66 
4-52 
74 
4.69 
78 
4-59 
76 
4.02 
69 
4.26 
56 
4-47 
46 
1 
l 
■4- 
TEMPERATURE, AND DEATHS FROM PHTHISIS IN LONDON, ENGLAND, 
Table 10.—Exhibiting, by months, for a period of thirty years, 1545--1874, the relation of average deaths per week in London, 
England, from Phthisis, to the average atmospheric temperature for the same period of time. This table is graphically represent- 
ed in Diagram 10. 
Thirty Years, 1845-1874. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. deaths per week from phthisis . . . 
Av. temperature, degrees Fahr 
154 
38.6 
153.25 
40.1 
160.2 
40.2 
162 
48.5 
157-25 
52.7 
150 
60.0 
H4-75 
64.2 
136.50 
63-5 
132-4 
59-1 
135-75 
52.2 
146 
44-2 
H7 
40.5 TEMPERATURE, AND SICKNESS FROM CONSUMPTION IN MICHIGAN. 
Table ii.—Exhibiting, by months, for a period of nine years, 1878-1886, the relation between sickness in Michigan from con- 
sumption, and the average atmospheric temperature for the same period of time. This table is graphically represented in Dia- 
gram 11. 
Niue Years, 1878-1886. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
'Nov. 
Dec. 
Av. percentage of reports of sickness. . 
Av. temperature, degrees Fahr 
65 
20.72 
68 
22.68 
69 
30-23 
70 
44.06 
67 
55-84 
65 
64.83 
63 
70.27 
6l 
67.88 
62 
61.43 
64 
35-87 
64 
35-87 
63 
25-47 
TEMPERATURE, AND DEATHS FROM BRONCHITIS IN EONDON. 
Table 12.—Exhibiting, by months, for a period of thirty years, 1845-1874, the relation of average deaths per week in London, 
England, from bronchitis, to the average atmospheric temperature for the same period of time. This table is graphically repre- 
sented in Diagram 12. 
Thirty Years, 1845-1874. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov.* 
Dec. 
Av. deaths per week from bronchitis . . 
Av. temperature, degrees Fahr .... 
193-5 
38.6 
172.5 
40.1 
165 
42.2 
127-5 
48.6 
90.0 
52.7 
63.2 
60.0 
48.25 
64.2 
41.0 
63*5 
48.2 
59-1 
76.5 
52.2 
141.25 
44.22 
190.2 
40-5 
TEMPERATURE, AND SICKNESS FROM CROUP IN MICHIGAN. 
Table 13.—Exhibiting, by months, for a period of ten years, 1877-1886, the relation between sickness in Michigan from mem- 
branous croup and_ the average atmospheric temperature for the same period of time. This table is graphically represented in Dia- 
gram 13. 
Ten Years, 1877-1886. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. percentage of reports of sickness. . 
Av. temperature, degrees Fahr 
2 
20.56 
10 
23.62 
8 
29.80 
7 
44-33 
5 
56.08 
4 
65.10 
2 
70.52 
3 
68.14 
4 
61.67 
6 
50.83 
9 
36.04 
10 
26.60 
Table 14.—Exhibiting, by months, for a period of three years, 1883-1885, the relation of sickness from “respiratory diseases” 
among the native troops in India to the average atmospheric temperature for the same period of time. This table is graphically 
represented in Diagram 14. 
TEMPERATURE, AND SICKNESS FROM “RESPIRATORY DISEASES” IN INDIA. 
Three Years, 1883-1885. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. cases of sickness per 1,000 soldiers . 
Av. temperature, degrees Fahr 
102.8 
68.7 
71.6 
70.6 
51.8 
79-i 
38.6 
83-9 
33-8 
85.2 
26.6 
84.8 
25-5 
83-3 
23-7 
82.7 
31-8 
82.3 
37-7 
80.5 
59-9 
74.2 
93-8 
69.1 
TEMPERATURE, AND SICKNESS FROM INFLUENZA IN MICHIGAN. 
Table 15.—Exhibiting, by months, for the ten years, 1877-1886, the average percentage of reports stating the presence of sick- 
ness from influenza in Michigan, also the average atmospheric temperature at stations in Michigan for the same period of time. 
This table is graphically represented in Diagram 15. 
Ten Years, 1877-1886. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. percentage of reports of sickness. . 
Av. temperature, degrees Fahr 
55 
20.56 
61 
23.62 
'Pen I 
OO'O 
0 
52 
44-33 
38 
56.08 
28 
65.10 
20 
70.52 
21 
68.I4 
29 
61.67 
33 
50.83 
4i 
36.04 
48 
26.60 
TEMPERATURE, AND SICKNESS FROM TONSIEITIS IN MICHIGAN. 
Table 16.—Exhibiting, by months, for the eight years, 1879-1886, the average percentage of reports stating the presence of sick- 
ness from tonsilitis in Michigan, also the average atmospheric temperature at stations in Michigan for the same period of time. 
This table is graphically represented in Diagram 16. 
Eight Years, 1S79-1886. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. percentage of reports of sickness. . 
Av. temperature, degrees Fahr 
60 
19.91 
6l 
21.77 
60 
28.82 
53 
43-04 
47 
55-98 
42 
64.79 
33 
69.78 
32 
66.25 
37 
61.ii 
45 
50.68 
55 
35-56 
60 
25.82 
Table 17.—Exhibiting, by months, for the nine years, 1877-1885, the average percentage ot reports stating the presence of sick- 
ness from bronchitis in Michigan, also the average atmospheric temperature at stations in Michigan for the same period of time. 
This table is graphically represented in Diagram 17, 
TEMPERATURE, AND SICKNESS FROM BRONCHITIS IN MICHIGAN. 
Nine Years, 1877-1885. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. percentage of reports of sickness. . 
Av. temperature, degrees Fahr 
77 
20.77 
78 
23.89 
77 
29.76 
72 
44.14 
61 
56-23 
54 
65-3° 
43 
70-73 
41 
68.23 
49 
61-73 
55 
50.72 
67 
36.23 
72 
27.28 16 
TEMPERATURE, AND SICKNESS FROM PNEUMONIA IN MICHIGAN. 
Table 18.—Exhibiting, by months, for the eight years, 1877-1884, the average percentage of reports stating the presence of sick- 
ness from pneumonia in Michigan, also the average atmospheric temperature at stations in Michigan for the same period of time. 
This table is graphically represented in Diagram 18. 
Eight Years, 1877-1884. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. percentage of reports of sickness. . 
62 
66 
62 
56 
42 
27 
17 
14 
18 
23 
36 
48 
Av. temperature, degrees Fahr 
21-43 
25.60 
31.04 
44.48 
56.60 
65-54 
70.68 
68.85 
62.05 
51-34 
35-99 
27-25 
ABSOLUTE ATMOSPHERIC HUMIDITY, AND SICKNESS PROM PNEUMONIA IN MICHIGAN. 
Table 19.—Exhibiting, by months, for a period of ten years, 1877-1886, the relation of sickness in Michigan from pneumonia to 
the average absolute humidity. The two lines in this table are graphically represented in Diagram 19. 
Ten Years, 1877-1886. 
Annual 
Av. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Sickness from pneumonia . . . 
Average absolute humidity . . . 
36-5 
3-44 
57-9 
1.38 
63-1 
I-5I 
6l.I 
I.8l 
53-9 
2-75 
39-3 
3-91 
25-1 
5 27 
16.1 
6.07 
13-3 
5-84 
16.7 
4.98 
21.3 
3-7i 
33-4 
2.30 
44.8 
1-73 
TEMPERATURE, AND DEATHS FROM PNEUMONIA IN LONDON, ENGLAND. 
Table 20.-—Exhibiting, by months, for the thirty years, 1845-1874, the average number of deaths from pneumonia in London, 
England, also the average atmospheric temperature for the same period of time. This table is graphically represented in Dia- 
gram 20. . 
Thirty Years, 1845-1874. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. deaths per week from pneumonia . 
Av. temperature, degrees Fahr 
98 
38.6 
86 
40.1 
91 
42.2 
82 
48.6 
67 
52.7 
53 
60.0 
42 
64.2 
37 
63-5 
3* 
66 
52.2 
98 
44.2 
108 
4°-5 
TEMPERATURE, AND SICKNESS FROM SCARLET FEVER IN MICHIGAN. 
Table 21.—Exhibiting, by months, for a period of ten years, 1877-1886, the relation which the sickness in Michigan from scarlet 
fever sustained to the atmospheric temperature ; Exhibiting the average atmospheric temperature, and what percentage of all 
weekly reports received stated that scarlet fever was under observation of the physicians who made the reports. (Over 41,000 weekly 
reports of sickness, and over 190,000 observations of the atmospheric temperature are represented in this table). This table is graph- 
ically represented in Diagram 21. 
Ten Years, 1877-1886. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av, percentage of reports 
Av. temperature, degrees Fahr 
22.3 
20.56 
23-5 
23.62 
23-9 
29.80 
21.6 
44-33 
19.6 
56.08 
17.0 
65.IO 
13-7 
70.52 
11.8 
68.14 
12.5 
61.67 
16,0 
50.83 
17-3 
36.04 
18.1 
26.60 
Table 22.—Exhibiting, by months, for thirty years, 1845-1874, the relation between the weekly average number of deaths from 
small-pox and the average atmospheric temperature in London, England. Records of 30,000 deaths are included in this table. This 
table is graphically represented in Diagram 22. 
TEMPERATURE, AND DEATHS FROM SMALL-POX IN LONDON, ENGLAND. 
Thirty Years, 1845-1874. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. weekly number of deaths 
Av. temperature, degrees Fahr 
23.00 
38.6 
24.00 
40.1 
21.60 
42.2 
23-75 
48.6 
24.50 
52-7 
22.40 
60.0 
18.00 
64.2 
14.25 
63-5 
13.00 
59-1 
13.00 
52.2 
14-50 
44.2 
18.20 
40-5 
Table 23,—Exhibiting, by months reduced to uniform length—3o days each—for the four ybars, 1862-65, the average number of 
deaths from consumption per 100,000 soldiers (“mean strength”) of the white troops of the U. S. Army in the war of the Rebellion in 
comparison with the average atmospheric temperature at six stations representing approximately the latitude and longitude of the 
aggregate forces of the Armies of the United States. 
DEATHS FROM CONSUMPTION IN WHITE TROOPS, U. S. ARMY, AND TEMPERATURE. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Av. No. of Deaths per 100,000 of M. Str. 
Av. Temperature at Six Stations 
19-55 
36 
22.47 
38 
19-63 
54 
17.00 
66 
16.07 
74 
17-38 
78 
15-75 
76 
14.96 
69 
'“vo 
£r10 
17-13 
46 
18.06 
38 
Table 24.—Exhibiting by months for a period of nine years, 1877-85, the relation of sickness in Michigan from diphtheria to the 
average atmospheric temperature. 
SICKNESS FROM DIPHTHERIA IN MICHIGAN, AND TEMPERATURE- 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
J«iy- 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Per cent, of Weekly Reports 
Average Temperature 
29 
20.77 
25 
23.89 
22 
29.76 
21 
44-14 
18 
56.23 
l6 
65 30 
15 
70-73 
l6 
68.23 
19 
61-73 
27 16 
50.72 
30 16 
36-23 
29 
27.28 
16 It would seem possible that this sudden great increase of sickness from diphtheria may, in part, be due to the spreading of the 
disease incident to the opening of schools in the autumn. 
Note.—Data for this table and the diagram illustrating it are found in Exhibit XIII, p. 122 ; and in the upper line of Exhibit V, 
p. 24, Annual Report of the Michigan State Board of Health, for 1886. 17 
Croup and 7e?nfieraCure, in. Mj ass a ohttselfs. 18 
TiiagramZ—Crou fi and* </ihsolute tii*m idtty in JH*ass<zchtisoffs.  Consu rrvfdXo* and* %ir\j>ercXu re Vft JKeassdcJtsecM. 20 
Dingfamif.- Sm<ZH~J»ox and itvJtassachu.s*tts. 21 
Qicr&i’ctTniK-JJrJrfrfJteriit and Oimh& rcUure, in JHassachusetts. 22 
Vi 6.-fneurnonicu and Jemperatute in JlflassachiLsett<s. 23 
ViagffT'm capiatinct Xtrvdj Jeynfi&ratlL-r& bn M.aLSS<Zch4J/s&tt^. 24 
Uiagmrn &. Jemperaturefand Sichn ess from Tneumoma in U.S. Armies. 25 
Diagram cf.-Si d<ness from Co ns urn pit an, zrt /{Jntt Jroops, 
'U.S.JIrmy, and JemperaiLcre 26 
JCA.—'Zctrybej-dt/u/'e-, fj//svm /jbf/z/sis u* 27 
/es/ipei'a cincl sickms?ypnn tfcr? sumfifuw . 28 
as?d yho/nJ/rvncJt//*.T 7X irfJldcn'. 29 
'O'lustz, c/nct. Aicti/jess /rvm C'rcitJj tnjMichiqan 30 
'Try/y/jSJ r//s//f , r/s/r/ S/r/fs//’ v/ y>vw ‘fas/Hra/tsf /fa/xtui ui 7s*r/t&' 31 
NO. 15.—TEMPERATURE AND SICKNESS FROM INFLUENZA IN MICHIGAN. 32 
NO. 16.—TEMPERATURE AND SICKNESS FROM TONSIEITIS IN MICHIGAN. 33 
NO. 17.—TEMPERATURE AND SICKNESS FROM BRONCHITIS IN MICHIGAN, 34 
NO. 18.—TEMPERATURE AND SICKNESS FROM PNEUMONIA IN MICHIGAN. 35 
NO. 19.—ABSOLUTE HUMIDITY, AND SICKNESS FROM PNEUMONIA 
IN MICHIGAN, 36 
NO. 20.—TEMPERATURE AND DEATHS FROM PNEUMONIA IN EONDON 37 
NO. 21.—TEMPERATURE AND SICKNESS FROM SCAREATINA IN MICHIGAN 38 
no, 22.—TEMPERATURE AND DEATHS FROM SMALL-POX IN LONDON 39 
Diagram Z3..Deaihs from Corsumflion in U.S. Armies, ard Temperature, 40 
Viag ram 24.-Siekve ssfrom Tern p erature 7p Mick igcm. RECENT SAVING OF LIFE IN MICHIGAN. 
In a carefully-prepared paper, read before the Sanitary Convention at 
Vicksburg, the proceedings of which are just published. Dr. Baker gave 
official statistics and evidence which he summarized as follows : 
“ The record of the great saving of humau life and health in Michigan in 
recent years is one to which, it seems to me, the State and local boards of 
health in Michigan can justly ‘ point with pride.’ It is a record of the 
saving of over one hundred lives per year from small-pox, four hundred 
lives per year saved from death by scarlet fever, and nearly six hundred 
lives per year saved from death by diphtheria—an aggregate of eleven 
hundred lives per year, or three lives per day saved from these three dis- 
eases! This is a record which we ask to have examined, and which we are 
willing to have compared with that of the man who ‘ made two blades of 
grass grow where only one grew before.’ ”