* THE CLIMATE OF COLORADO l,FOK 
T? resIPTR A TORY 
BY CHARLES DENISON, A.M., M.D. 
Emeritus Professor of Diseases of the Chest and of Climatology, 
University of Denver; Ex-President of the American 
Climatological Association, etc. 
DENVER, COLO. 
PART I.—THE ATTRIBUTES OF CLIMATE AND 
AIR-RAREFACTION. 
The request of our Chamber of Commerce Commit- 
tee, to give the facts concerning the kind of climate 
we have in the vicinity of Denver, is complied with 
reluctantly, only because the author fears his inability 
to do the subject justice in the space allotted. The 
evidence depended upon is too voluminous to mention 
it all, and the author will have to refer the reader to his 
other writings 1 for the details, and to state some pos- 
itive conclusions, which might otherwise be challenged 
if they were not based upon a twenty-four years resi- 
dence in Colorado, in which time some thirty-tive 
hundred pulmonary cases have been recorded. Ex- 
perience is what tells, and the experience of the med- 
ical profession in Colorado unquestionably sustains 
the conclusions here presented. We may differ as to 
the advisability of inviting the weaker, the invalid 
i “The Kooky Mountain Health Resorts,” Cloth and Paper covers. 
Houghton. MltHin ami (Jo , Boston, Publishers. Descriptive of the 
interior health resorts of the United States. “The Climate of the 
United States In Colors.” The W. r. Keener Co.. 9o Washington st. 
Chicago, Publishers. A graphic description, in twelve colored 
charts and eleven tabulations, of over 8,0oo,000 separate observations 
of the United States Signal Service Bureau, given in Annual and 
Seasonal representations of cloudiness, temperature, rainfall, winds 
and combined humidity statistics, for the professional and lay refer- 
ence. "The Preferable Climate for Consumption.” Congresses of 
lKTil and 1K*7. Somewhat elaborate arguments founded upon the 
analysis of climatic attributes Independent of locality. 
•(Reprinted from the Journal of the American Medical Associa- 
tion of May 7th and 14th, 1898.) 2 
class to come out here and live. The fact remains, 
however, that our recovered invalids have ceased to be 
a detriment to the communities in which they have 
mingled and that they constitute, in a large degree, 
the life and success of our new civilization. It is 
therefore with hope and confidence that we refer to 
the proofs which substantiate our experience in this 
elevated section. 
Before proceeding with the summary of the evi- 
dence on hand, let it be admitted that some medical 
minds are not wholly in accord on the question of 
climatic effects in the causation and cure of disease, 
probably because of local bias or that their estimation 
of the attributes of climate is measured by a limited 
experience. This is unfortunate, but has to be ad- 
mitted if any credence is to be given to such medical 
gatherings as the late “ Congress of Medico-Climatol- 
ogy, Auxiliary of the World’s Fair.” At that meeting 
reports were presented from widely separated districts, 
high, low, inland, sea bounded and both within and 
without the United States. These reports were so 
exaggerated in praise of each special locality repre- 
sented, that the listener, without a settled basis of 
judgment as to preferable climatic attributes, would 
be deceived into acquiescence to absurd propositions 
in turn alike contradictory. This going into the min- 
utiae of local weather statistics (as the daily range of 
temperature, or the extremes reached in a given 
month or year) as many have done, is of questionable 
use. 
Such a mass of unessential particulars, however 
laboriously tabulated, only consumes time in its study 
and detracts from the consensus of knowledge 
needed.2 3 
Climate has to do with many special diseases, and 
2 To be commended: A recent historical and geographical study of the 
climates of that part of the world inhabited by the Engish-speaking 
people, issued by MacMillan and Go., London and New York, on 
*• The Treatment of Lung Diseases by Climate,” by Dr. C. Theodore 
Williams. 
3 “A Handbook of Medical Climatology” by S. Edwin Solly, M.D., 
M.R.C.S., Lea Bros, and Co., Publishers, Philadelphia and New York 
1897. 3 
its effects upon kidney diseases, the nervous system, 
age, sex and occupation would be instructive if time 
permitted to consider them; but we are now to study 
chiefly the class of diseases with which climate has 
both the greatest causative as well as curative effect, 
namely: 
Chronic pulmonary diseases.—This study4 of fhe 
air with regard to the causation and cure of respira- 
tory diseases ushers us immediately into a controversy 
which has more than any other occupied the atten- 
tion of climatologists for the past thirty years. It is 
the question of air pressure and the susceptibility or 
adaptability of the human organism to it under vary- 
ing states of health and disease. Without seeming to 
oontrovert the great general argument, that of purity 
of atmosphere, always used by those who do not 
admit the importance of this air pressure considera- 
tion (for the pure air argument is an admitted issue 
and needs no proof), the question of altitude or sea 
level pressure can not, we believe, be ignored in the 
climatic prescription we are required to inscribe. 
The purpose in the following presentation is to 
ignore any given locality and consider the chief attri- 
butes, those variously considered as most effective in 
the production of what is called climate. These are; 
1, elevation al)ove the sea (rarefaction); 2, dryness of 
the air, both absolute and relative; 3, temperature of 
the air, whether cold, cool or warm; 4, sunshine, its 
preponderance or average daily duration at a given 
place, which introduces the important questions of 
cloudiness and the diathermancy (clearness) of the 
air; 5, the winds which introduce many correlated 
causes, such as the seasonal changes, the configuration 
of the earth’s surface at a given place, the ocean tide, 
storm winds, daily or periodical currents of mountain 
or sea air, etc; G, the character of the soil, which is of 
great importance with reference to the proportion of 
forests to dry land, the contiguity of the sea or large 
* Larpelv drawn from the Author's article on '‘Climatic Treatment ” In 
Foster’s Practical Therapeutics 4 
bodies of water, and the general configuration of the 
earth’s surface; 7, the variability or equability of the 
air-temperatures, which are largely relative, the former 
to altitude and the latter to the sea; 8, the electric 
condition of the atmosphere, which mysterious agent 
is also decidedly relative to mountain and sea currents, 
but which is none the less important as affording 
desirable stimulation. 
In choosing from such attributes the most desirable 
combination for the arrest of lung disease, the writer 
feels called upon to explain why he does not place 
altitude the most important of all, at the head of the 
following list. It is; 1, because altitude shows its 
effect upon each important attribute, and thus in a 
fair analysis gets a reasonable allowance of praise; 2, 
because the special consideration of altitude is needed 
in presenting air-rarefaction as a potent force in treat- 
ing respiratory diseases, hardly second, by itself, to 
any other attribute, yet at least entitled, in the minds 
of the majority of physicians, to hold the third place 
in such a classification. 
Dryness is preferable to moisture.—We should have 
a line of demarcation between these two opposing 
qualities of the atmosphere, so that there could be no 
confusion in the use of the terms dryness and moist- 
ure. It seems that the average of the combined 
hygrometric conditions of the atmosphere, for the 
whole inhabited portion of the country, is a fair crite- 
rion between these two opposite conditions, and we 
will accept this as the line of definition between dry- 
ness and moisture. Temperature must be accounted 
for, as the capacity of the air to hold moisture varies 
so greatly, according to this record, the variation being 
from about one-half grain of vapor to the cubic foot, at 
zero, to nearly twenty grains at 100 degrees F., when 
the air is' saturated. This was the foundation of the 
writer’s rule for the determination of moisture and 
dryness.5 
5 “ Moisture and Dryness.” Report made to the American Climatological 
Association, 1884, Rand, McNally and Co., Chicago. 5 
This rule was based upon a calculation of a table 
representing the average of the combined humidities 
of the air (cloudiness, absolute and relative humidity) 
for the whole United States, and for every degree of 
temperature. The average of these three evidences 
of humidity were found to be 44.5 per cent, for the 
time (average proportion of each day) the sky was 
clouded, 07 percent, of saturation, for relative humid- 
ity, and, consequently, 07 per cent, of the weight of 
vapor the air could hold, for absolute humidity. 
The graphic illustration of this rule on colored 
maps, compared with mortality statistics, shows that 
the arrest of consumption is far more surely to be 
accomplished as you go toward the extreme of dry- 
ness, from the mean, than toward the extreme of 
moisture. Indeed, it is the very moist climates which 
furnish most of the cases to be arrested in the dry 
sections. 
The chief argument in favor of atmospheric dryness 
is based upon the increased transpiration of aqueous 
vapor from the lungs, in a degree according to the 
dryness of the air breathed. The germs of disease 
need warmth and moisture in which to live and flou- 
rish, a climate tempered and constituted according to 
the requirements of their peculiar oxistence. It is 
reasonable to infer that the preference shown by 
tubercle bacilli for a locus habitandi in pulmonary 
tissue is in no small degree governed by the catarrhal 
or other products of inflammatory change which clog 
or close the air cells and connecting tubes. If these 
secretions or morbid products could be removed at the 
same time the bacilli which inhabit them were thrown 
otf. the result would certainly be salutory. These 
could be so expelled if they could be reached by the 
inhaled air, and this in turn had the requisite absorb- 
ent power. This absorbent power is just what the 
inhaled air possesses through its quality of dryness, 
and in proportion thereto. Absorption takes place 
through the difference in percentage of saturation 
(relative humidity) between the inspired and the 6 
expired air, and also much more through the differ- 
ence in quantity (absolute humidity) between the 
moisture inhaled and that expelled. This especially 
takes place if cold air is inhaled, which is raised to 
the temperature of the body and then has greater 
power for holding moisture. Valentine, Sanctorius, 
Lavoisier, Seguin, Dalton and others have investi- 
gated the subject of transpiration, but not to differen- 
tiate between persons at different altitudes and tem- 
peratures. In this analysis of humidity statistics, 
(“Moisture and Dryness”) the writer made an at- 
tempt to compute the difference in transpiration. He 
took Draper’s statement as the basis of his calcula- 
tions, namely, that the dew-point (the temperature at 
which the vapor present would make saturation) of 
the expired breath is 94 degrees, F. Three kinds of 
estimates were made by way of comparison. 
1. Difference in vapor transpiration between a warm 
moist (Jacksonville, Fla.) and a warm dry climate 
(Yuma, Ariz.), of about the same elevation and tem- 
perature. This calculation, for an ordinary sized 
man, gave for Yuma, 3937 grains vapor exhaled, and 
3073 for Jacksonville, or an excess for Yuma over 
Jacksonville of 864 grains a day, when no exercise 
was taken. When one makes allowance for the in- 
creased respiratory activity due to exercise, he can 
realize the still greater difference in transpiration as 
shown by Dr. Edward Smith’s statement that, “one 
at sea level, walking at the rate of three miles an hour, 
consumes three times as much air as when at rest.” 
The ordinary exercise of a man would make this dif- 
ference in transpiration under the given conditions 
equal to about a gill in twenty-four hours. 
2. When we make this calculation for places of 
different temperatures and elevations, the evidence 
becomes still more conclusive, for cold is probably 
the most important factor in the production of dry- 
ness, and elevation is not far inferior, because it, in 
turn, produces cold as well as expansion in the vol- 
ume of the air. It is right to allow for the elevation 7 
an equivalent to the proportionate rarefaction of the 
air, that is, if the pressure is one-fifth less (twelve 
pounds to the square inch) at Denver than at Jack- 
sonville, then one-filth more air will be breathed at the 
former station. In this calculation we will assume a 
good sized man, JO years old, as breathing both in 
Denver and Jacksonville twenty breaths a minute 
and thirty cubic inches to a breath (Dr. Grehant), 
ordinary exercise included, and for the same season 
at each place. This gives by the same method of 
reckoning, vapor exhaled ubove that inhaled in twen- 
ty-four hours, 8000 grains for Denver and 4039 for 
Jacksonville. This is an excess of transpiration of 
moisture in favor of Denver of 3001 grains, or over 
8 ounces, in twenty-four hours. Two important con- 
siderations would further add to this effect in favor 
of the high altitude station: a, the expansion of the 
air, in being raised in the respiratory tract from the 
lower temperature of the atmosphere to the higher 
temperature of the body, />, the increased amount of 
exerciso naturally indulged in at the higher station, due 
to the stimulation of the cold, and the possible electric 
influence, quickening and deepening respirations. 
3. For the purpose of still further comparison, it is 
instructive to take a cold, dry place in winter (Chey- 
enne, Wyo.) and a warm, moist one in summer 
(Charleston, S. C.) on the same basis (though Chey- 
enne is a little more elevated than Denver). The 
calculation results in vapor exhaled above that inhaled 
in twenty-four hours, 0881 grains in Cheyenne and 
3(115 in Charleston; excess of respiratory evaporation 
in favor of Cheyenne in winter, over Charleston in 
summer, is (>2(ifi grains. If the two modifying effects 
previously mentioned were to be taken into consid- 
eration, together with the usually increased activity 
of the respiratory organs in such cold, as compared 
with such warm weather, the result would show for 
Cheyenne in winter a daily passing of vapor from 
the lungs of at least a pint more, than for Charleston 
in summer. 8 
Coolness or cold is preferable to warmth or heat. 
The importance of cold in the composition of the 
curative atmosphere we seek is hardly less than that 
of dryness. In fact the two are so interdependent 
and necessarily associated that they can not be easily 
separated. If the thermal units coming from the 
combustion of effete material which should be thrown 
off through the lungs may be considered as indices of 
the natural cleansing of the system, then the tremen- 
dously augmented expenditure of heat units required 
in cold climates to maintain an equilibrium of bodily 
temperature must be credited for this great purifying 
influence. This potent effect is still further increased 
by the greater transpiration of vapor from the lungs 
in dry, cold climates, above proved to take place, 
because such transpiration is represented by the latent 
heat of vaporization, also necessarily thrown off. 
This temperature problem naturally introduces the 
following considerations: 
1. How much atmospheric humidity is influenced 
by the element of temperature is shown by the sen- 
sory effect of cold. It is through conduction chiefly, 
that the body parts with its heat. Evaporation and 
radiation together do not equal this power of conduc- 
tion, which the atmosphere, in common with every- 
thing that touches the body, possesses. Now, the 
conductivity of the air depends greatly upon its 
moisture. It is with the air as it is writh solid sub- 
stances. A bar of iron feels very much colder than 
the same shaped piece of dry pine, though they both 
may be of the same temperature. The iron is by far 
the better conductor, just as moist cold is, compared 
with dry cold air. To those who have never previ- 
ously experienced a dry, cold and sunny morning on 
the eastern slope of the Rocky Mountains, there is a 
deception in the sensation of cold, which is equivalent 
to from 15 to 20 degrees. One seems to be in a much 
warmer atmosphere than that in which he really is. 
Temperature then is a relative attribute, and can not 
be considered as independent of humidity. Besides, 9 
the drying effect of cold upon the atmosphere, low 
temperature will be found to have other useful effects 
in the arrest of consumption. 
2. Heat expands the air, so that the confrast be- 
tween the temperature of the atmosphere and that of 
the body indicates the swelling effect cold air pro- 
duces when full breaths are taken. Any doubt about 
this may be settled by trying the simple experiment 
of breathing one’s utmost into a spirometer in a heated 
room when the air is frozen outdoors. Then step to 
the door, take a full breath and try again; the differ- 
ence should in part indicate the expanding force heat 
imparts to the inhaled air. This lung-stretching 
capacity of inhaled cold air is especially appreciated 
by those who hold that it is most often the lack of 
use which paves the way to infiltrations or tubercular 
deposits in the tops of the lungs. It is to such 
secluded places in the lungs that the expanding air 
carries the evaporating influence of dryness. 
3. Cold stimulates and heat depresses. This is a 
generally accepted proposition, which needs no ex- 
tended elaboration. The sensations themselves are a 
good guide, and the colder the air the more stimu- 
lating it is. “A bright sun and blue sky overhead, a 
clear and quiet atmosphere, distant sounds transmit- 
ted to the ear through the still air, combine with the 
charms of the scenery to produce such buoyancy of 
spirits that a man is braced and invigorated for almost 
any exertion.” (Dr. A. Tucker Wise in “Alpine Re- 
sorts.”) It is in harmony with this stimulating effect 
of cold, that the respiratory function is diminished 
in activity in hot climates, and an increased amount 
of blood is found in the lungs of residents in cold 
countries, as shown by Parkes, Rattray and others. 
Dr. Francis, of the Bengal army, found, from a large 
number of observations, that the lungs were lighter 
in Europeans in India than the European standard. 
The increased quantity of blood circulating through 
the lungs means increased oxidation of the blood and 
renewal of tissue. The pulmonary lymphatics join 10 
in the increased activity, the nervous system is exhil- 
arated, and the whole nutrition is improved. 
Cold not only stimulates and encourages needed 
exercise, but under certain conditions it may result 
in a desirable sedative effect. The sleep which comes 
at night after a day’s exhilaration and excitement 
induced by cold is the most refreshing of all rest. 
The influence of cold in destroying or impeding 
germ life, especially the life of the bacillus of tuber- 
culosis, is a most important consideration. This is 
diametrically opposed to the fostering of nearly all 
germ life by moist and mild heat. If one has ever 
“camped out” on the top of a Rocky Mountain pass, 
he will ne’ver forget the stillness of that insectless and 
germless locality. The nightly freezing of the air, 
together with its dilution through lessened air pres- 
sure, is enough to render germ life impossible. But 
the best evidence is that which has reference to the 
climate and natural life conditions of the bacillus, 
limited as they are to a narrow range of temperature. 
“ The air we inhale does not perhaps so often con- 
tain the fully developed bacillus as is supposed by 
many people, for this microbe does not thrive in the 
air at the usual temperature, but requires, according 
to Koch, a temperature approaching that of the human 
body. Its growth entirely ceases below about 82 and 
above 107 degrees F., and it thrives best at about 98 
to 100 degrees, while other pathogenic microbes have 
a much wider field—for instance, the anthrax bacillus, 
which grows luxuriantly between 67 and 74 and up 
to 110 degrees.”6 
The study of seasonal effects in phthisis shows the 
salutary influence of cold. This may appear strange 
to those people of the North Atlantic, Middle and 
Lake States who flee south in terror of the winter 
weather. True, yet do not thousands yearly leave moist 
England for a winter stay in the frozen uplands of 
Switzerland? The force of this consideration is not 
6 Dr. Weber, in the “ Croonian Lectures on Chronic Pulmonary 
Phthisis.” 11 
appreciated except through a recognition of the im- 
portance of dryness. Notice on the winter seasonal 
map, previously referred to, the prevailing northwest, 
west and southwest winds, some one of them every- 
where moving toward the great interior lake region of 
the United States. The cooling of these air currents, 
causing condensation of vapor, with the addition of 
moisture already existing, is enough to produce cloudi- 
ness in this interior lake section for from six to eight- 
tenths of the winter season. The effect of the cold 
moisture renders this a climate to be avoided by 
enfeebled lungs. However, where the other attri- 
butes—dryness, elevation and sunshine—are favora- 
ble, the winter is the best time of the year for most 
consumptives. In cases suitable for positive treat- 
ment, these favorable climatic conditions, by means 
of this cooler temperature, can be increased to a 
climax of success not otherwise obtainable. The 
experience of invalids in Colorado bears out this con- 
clusion. It is to secure the cooler temperature in 
summer time that some of the consumptive patients 
from the plains are sent higher up to the purks and 
divides of the Rocky Mountains. The effect of the 
change is very generally good, and a tubercular fire, 
which had rekindled in Denver on the advent of warm 
weather, has been arrested, as appearances indicated, 
by a sojourn in a cool park 8000 feet above the sea. 
Rarefaction is better than sea-level pressure.—The 
consideration of elevation is divided into: 1, the effect 
upon other climatic attributes. Then aside from this 
there is the mechanical effect of rarefaction; 2, the 
physical influence upon man in health; 3, the influ- 
ence in disease and the experience of invalids; 4, the 
evidence of a oertain immunity from consumption. 
We have already referred to the influence of rare- 
faction in producing dryness and coolness. Its effect 
upon sunshine, diathermancy, variability of tempera- 
ture, wind movements, radiation, evaporation, etc., 
will appear as we proceed. The expansion of the air 
is equivalent, in degree, to any given elevation. The 12 
additional space occupied carries with it its due pro- 
portion of atmospheric moisture. In localities favor- 
able for health resorts, this deprivation more than 
counterbalances the condensation of vapor by cold. 
The result is a total decrease of moisture, which is 
shown by a small percentage of cloudiness, a low rel- 
ative and a very small absolute humidity. Then 
through its expansive effect as well as by its influence 
upon other producers of dryness, elevation is a pow- 
erful agent in controlling atmospheric humidity. As 
to temperature, elevation has a constant effect in the 
production of cold. It is differently estimated by 
authors, but does not vary greatly from about 3 de- 
grees decrease in heat for each 1000 feet rise in eleva- 
tion. In some favorable localities, such as the eastern 
slope or base of the Rocky Mountains, this lowering 
temperature is neutralized by local conditions, such 
as the excess of sunshine, the character of the soil— 
being dry and sandy—and the protection of mountain 
ranges, which drain the western, humid air currents 
of their moisture, so that the isotherms, as a given 
elevation is reached, continue directly in a western 
course until the very high mountains turn them south- 
ward. 
The physical effect of rarefaction upon human 
beings.—Dr. Jourdanet, of Paris, gave us a most com- 
plete and elaborate exposition of the physiologic 
effects of the diminished air pressure, and not con- 
tent with this analytical investigation, he induced 
Paul Bert to work out by experiment, chiefly on the 
life of birds, the effects of the equivalents of various 
elevations, even up to starvation limits, as to the sup- 
ply of oxygen. These and many other studies might 
be elaborated if space permitted. Ignoring their 
trivial differences, we will state only settled 
sions. Lessened atmospheric pressure leads to an 
equivalent loss of oxygen, which deficiency, Parkes, 
in his “Practical Hygiene,” says is not felt by animals 
till a rarefaction equal to 14 per cent, is reached. 
This loss is about equivalent to an elevation of 10,000 13 
feet, and many animals do begin to live an abbrevi- 
ated existence at this height. Blit there are previous 
effects which man can appreciate all the way from 
3000 to 0000 feet, at which latter limit the air is one- 
fifth rarefied. This appreciation, in a state of rest, is 
from nothing to considerable, according to the sensi- 
tiveness of the heart or lungs, or both of them. There 
is an adaptability of these organs in perfect health 
which more than compensates for a rarefaction of 
one-fifth, so that only a pleasant exhilaration is felt, 
even with moderate exercise. Much exertion strains 
this adaptability, and a degree of breathlessness may 
be reached, which indicates a decided deficiency of 
oxygen compared with the immediate requirements. 
However, it is not the point of injury or danger that 
is here referred to, but the altitudes which produce 
healthful and well-borne respiratory activity when at 
rest and even during moderate exorcise. The effects 
of altitude vary according to the pulmonary or cardiac 
susceptibility of an individual, and are divided into, 
1, first effects; 2, permanent effects or acclimatization. 
On the arrival of a healthy individual in a high 
altitude, say a mile above sea level, there is first an 
increase, both in frequency and depth of respiration. 
When adjustment to the new conditions has taken 
place, which requires a variable period, according to 
the altitude and the individual, the respirations are 
not nearly so much increased in frequency during 
rest, but the depth of breathing is habitually greater. 
This is shown by the large spirometric records of 
those who reside at great elevations, and the increased 
size of their dusts both in adults and children. This 
is farther shown by the necessity of the climatic 
change to supply the usual, if not augmented, demand 
for oxygen, which is to meet an increased combustion 
or change of tissues. The increased exhalation of 
carbonic acid and the lower air temperature, as well 
as the increased chest measurements in those invalids 
who are not so far advanced in disease but that the 
affected lung tissue can be returned to use (an effect 14 
noted in the writer’s cases, as well as those of C. T. 
Williams, Weber and others), are in perfect accord 
with the habitual use of more air for all the purposes 
of living in high altitudes. The heart and lungs hav- 
ing a reciprocal relation to each other, are both pro- 
portionately more active. In imperfect respiratory 
states, such as incipient consumption, the impeded 
circulation feels the stimulation, especially in those 
portions of the body which were the least active before 
—in the lung periphery and the capillary system gen- 
erally. -The result is a more perfect circulation of 
the blood and oxygenation of tissues, also of carbon- 
aceous and effete materials. The supply and waste 
are more completely attended to, and the “sewer work” 
of the respiratory system is more complete. There 
is a change in the relative density of the air in the 
lungs, due to this increased activity and to the fact 
that the air breathed is rarefied. There exists an 
alternate greater pressure or density of the air with 
expiration, and diminished pressure or rarefaction 
during inspiration, with each respiratory act, com- 
pared with the air pressure outside the body, and also 
compared with the usual change of density of air in 
the lungs during respiration at sea level. Here is 
found the best form of “pneumatic differentiation” 
because it is natural. This increased outward pressure 
within the lungs is especially salutary in the chronic 
thickenings, etc., of the lining membranes of the air 
cells and bronchial tubes, and it has a tendency to 
open up passages closed by disease and non-use to 
the entrance of pure, dry air. Some of the worst cases 
of consumption are those where the air can not reach 
the microbes or morbid products. 
The augmented respiratory activity.—This with 
the rush of blood into and through the pulmonary 
capillaries, which seem to disturb the judgment of a 
few physicians with reference to the liability to 
the occurrence of pneumonia or pulmonary hemor- 
rhage in high altitudes, requires some further ex- 
planation. 15 
There is no cause for fear of hemorrhage if proper 
precautions are taken as to extreme elevations and the 
character and stage of the disease existing in the 
lungs. There should be no spots of softened lung 
tissue, especially near the root of the lung which have 
not had time to be protected by nature’s great con- 
servative process—the deposition of fibrous or hard- 
ening tissue. Only those patients should be sent to 
very high places who can bear the rapid expansion 
and augmented circulation without rupture of blood 
vessels. In portions of the lungs where there is no 
softening this increased pressure acts helpfully on the 
distended vessels, just as a properly adjusted bandage 
does on a swollen limb. The alternate crowding of 
the dry air against hypertrophied or diseased alveolar 
walls, and the suction directly applied through the 
push given to the circidation, tend to clean out the 
products of morbid processes and relieve congestion. 
There is, as mentioned by Dr. C. T. Williams, 1, 
hypertrophy, or more complete development of cer- 
tain portions of healthy lung tissue; 2, emphysema 
(dilation) of other portions, especially of those in the 
neighborhood of the consolidations and cavities. This 
increased action and the stretching help to isolate 
caseous or tubercular portions, prevent the spread of 
infection, and promote cicatrization or fibrination of 
the affected parts. 
As to pneumonic and hemorrhagic cases, the wri- 
ter's later experience tallies well with that tabulated 
in his report to the International Medical Congress of 
187b, in which were presented his first records of 202 
consumptives who had spent a total of 350 years in 
Colorado. The pneumonic cases and the hemorrhagic, 
without cavity, were by far the best influenced of all 
varieties. Very acute cases, during' the time inflam- 
mation or hemorrhage is active, need to be treated 
upon the rest principle, and such should be excepted 
from the foregoing. 
Altitude of immunity from phthisis.—There is pre- 
sumptive proof that those climatic conditions which 16 
prevail where phthisis seldom or never originates are 
best suited to arrest the disease when it has commenced 
elsewhere. Reference must be briefly made to the 
considerable evidence of medical writers in favor of 
an altitude of approximate immunity from consump- 
tion which, with us in America, ranges not far from 
8000 feet in the southwestern part of the United 
States; to nearly 5000 on our northern boundary. 
As to the quality of the climate which affords this 
partial immunity, Jaccoud of Paris, says, “ altitude 
is the most important element; climates with a high 
altitude, having tonic and stimulating effects, can 
alone confer on the inhabitants absolute or relative 
immunity from pulmonary phthisis.” While altitude 
is the governing element, all the associated favorable 
conditions of the atmosphere, somewhat in the order 
in which we have named them, seem to go hand in 
hand until they reach a climax of success in confer- 
ring a more or less complete immunity from consump- 
tion upon the residents at the given altitude. In 
illustration of this influence, the records of mortality 
from phthisis in the city of Denver and in Colorado 
generally, might be cited. Up to the year 1896, out 
of twenty deaths from this disease, eighteen or nine- 
teen were from the imported cases, a fact which should 
always be taken into account as explaining the mor- 
tality from consumption in this State. Since the date 
given, the consumptive mortality in the city of Den- 
ver has shown an increase undoubtedly due to local 
conditions in which a greater liability to infection has 
to be admitted. Even thus the proportion of indig- 
enous cases of tuberculosis to all deaths is now and for 
some time will continue to be far below that of any 
American city of like size. 
Sunshine is superior to cloudiness.—There is little 
necessity of advocating the utility of sunshine. Proof 
is sufficient, but is necessarily combined with that of 
other climatic attributes. Every one acknowledges 
the benefit of sunshine, though in summer time he 
may have a personal preference for shade. Undoubt- 17 
edly the effect of light upon man’s physical and moral 
well-being is analogous to the fructifying influence of 
the sun’s rays upon the vegetable kingdom. All life 
depends upon sunshine, and for successful existence 
must have it. The proportion of sunshine to cloudi- 
ness depends on the length of the day, on the expo- 
sure of a place, as on whether or not it is concealed 
in a valley, and on the cloudiness of the sky. The 
distribution of clouds in the United States is compu- 
ted by the Signal Service Bureau in tenths of obscu- 
ration of the sky, and from these observations the 
percentage of cloudiness, and conversely of approxi- 
mate sunshine, may be noted for the whole country. 
Reference is made to the first of the charts in the 
“ Climates of the United States, in Colors” already 
referred to, for an eleven year average of the distri- 
bution of cloudiness. The variations of cloudiness 
range from above 60 per cent, of the time over the 
interior lake region down to less than 30 per cent, in 
the southwestern portion (New Mexico and Arizona). 
Taking so broad a field into calculation, a striking 
harmony is noted between cloudlessness or sunshine, 
and other favorable attributes. They all go together. 
A preponderance of sunshine should be mentioned 
as favoring the possibility of the desirable outdoor 
life, and also of camping out in summer time. 
PART II:—SENSIBLE TEMPERATURE AND THE EXPERI- 
ENCE OF INVALIDS, WITH CONTRAINDICATIONS 
FOR THE HIGH ALTITUDE CLIMATE. 
Variability versus equability.—The study of tem- 
perature ranges assumes importance from the undue 
weight given by the medical profession and the laity 
to supposed injurious effects of thermal changes. 
Let us investigate and see if it is the dampness and 
not the thermal oscillation which is responsible for 
the injury. How uniformly variability goes with 
dryness and equability with moisture may be illus- 
trated by the daily and monthly ranges of tempera- 
ture at places which represent dry and moist climates. 18 
Chosen without reference to this particular evidence, 
twenty-five dry and twenty-five moist prominent sig- 
nal stations and health resorts in the United States 
give the following remarkable average excesses of 
mean daily temperature ranges. The excess of the 
dryest one-fourth over the moistest one-fourth of them 
is 22.9 degrees, and the same average excess for the 
monthly ranges of temperature is 2.1 degrees greater 
variation in the dry than in the moist localities. 
Again, taking the fifteen most and the fifteen least 
variable signal stations in the United States (out of 
136 stations) for the year, we have an average excess 
of temperature variability of the most over the least 
changeable stations for spring, 18.5; summer, 16.2; 
autumn, 17.6; winter, 16.5, and for the year, 16.8 
degrees F. The first fifteen are extremely dry with 
daily average for the year of 28.7, and the second 
fifteen decidedly moist localities with a daily average 
variability of only 11.9 degrees F. This evidence is 
conclusive that variability goes with dryness. 
Seasonal ranges of temperature likewise show the in- 
seperability of equability from atmospheric moisture, 
and ot variability from dryness. Compare the winter 
and summer temperature lines on seasonal charts. 
The sea is the great equalizing influence, and the 
colder land in winter turns these isotherms to the 
south for a considerable distance in the United States, 
viz., on the western boundary, about parallel with the 
coast. In the summer, however, when they leave the 
ocean, these lines are turned nearly as much to the 
north as the winter ones are to the south. The 
farther we get away from the humid influences the 
greater is the variability of temperature. It is not 
maintained that extreme variability should always bo 
sought or that of two places, with all other advantages 
the same, the more variable one is the better. On the 
contrary, the less variable would certainly be preferred 
in cold weather. It is maintained, however, that vari- 
ability is quite a uniform constituent of dry high 
places and that as the dryness predominates the marked 19 
variability is less felt and is less, if at all, objection- 
able. On the other hand, marked atmospheric equa- 
bility, wherever found, is prima facie evidence of 
excessive humidity. 
The worst that can be said against combining vari- 
ability with the favorable attributes of climate for 
consumption is that its defence is necessary in order 
to overcome a prevailing prejudice and to show that 
this variability is a sine qua non of the preferable 
combination. But there would be no excuse for 
advocating a false theory of climate, even if this one 
element were unfavorable. There is a prevalent 
exaggeration of the effect of temperature changes. 
The change gets the blame which rightly belongs to 
the element of humidity, which constituent is always 
excessive when a given change is injurious. For 
instance, a change of 20 degrees from a warmer to a 
colder temperature, with the relative humidity 50 per 
cent, does not equal in the sensation or shock to the 
system a change of 8 degrees with the relative humid- 
ity at 80 per cent. The former change does not pro- 
duce saturation, but the latter does; so does a change 
of 5 degrees with the humidity at 00 per cent., and 
even 2 degrees with the humidity a 95 per cent, of 
saturation (see Glashier’s table). Therefore it is the 
humidity of the air which, through conduction of heat 
from the body, makes a slight temperature change, 
with the air near saturation, equivalent to a much 
greater change with the air dry. It is one of the mis- 
takes of medical antiquity for equability to be insisted 
on as a constituent of the best climate for consump- 
tives, yet this seems to be a fallacy most difficult to 
correct. It is essential to insist upon equability for 
humid climates, but for dry, cool, elevated resorts it 
is out of the question. There is something wrong 
with the reasoning powers of an author who jumbles 
together climatic attributes so that his “ideal climate” 
has no real counterpart among the known climates of 
the world. The trouble is chiefly with the vague use 
of the words equability and variability. Until now 20 
there has been no accepted line of definition between 
these two terms. This we should have. If the mean 
of variability for the whole country were taken as a 
just division, and the daily and monthly ranges of 
temperature were the criterion to decide by, we would 
then have a division line approximately represented 
by 18 to 20 degrees F. for the daily, and 46 to 48 for 
the monthly range, the same being in harmony with 
the dividing line between moisture and dryness on 
the writer’s climatic charts. This is a fair line of 
division which is commended for general adoption, 
especially by those authors who write about equability 
as essential to pulmonary resorts. 
Actual versus sensible temperature.—Captain W. 
A. Glassford, signal officer United States Army, Den- 
ver, Colo., has given much attention to comparing 
the actual with the apparent climate in Colorado. 
Omitting interesting but lengthy illustrations, he 
says: “ Taking the city of Denver, we find that dur- 
ing the year there are 172 days on which the daily 
mean temperature is above 50 degrees F. and 64 days 
below 32. The 50-degree point is the lowest mean 
temperature which mankind considers comfortable, 
and it is the critical point as regards the growth and 
development of the most important staple crops. The 
same number of comfortable days prevail during the 
year at Albany, N. Y., as here, but instead of 64 they 
have 107 days with temperature below 32 degrees 
(freezing). 
“ Let us now turn to a few facts as to Colorado sum- 
mers. Denver is on the line of 105 degrees extreme 
maximum temperature, that being the highest ever 
observed here. To the west of this line these extremes 
diminish and to the east they increase. 
“I wish, here, to draw particular attention to the 
unfairness—unintentional to be sure—to which Colo- 
rado and the entire West is subjected in the official 
consideration and publication of its record of heat as 
affecting animal life, in that there is overlooked the 
important element of dryness, which moderates the 21 
sensible effect of the extremes of heat as well as of 
cold. There are in all temperature records two ele- 
ments—the sensible temperature or that which ex- 
presses the heat or cold felt by the human beings, and 
the apparent temperature, a mere record of how the 
mechanical thermometer is affected. It is the appa- 
rent that receives publication, greatly to the undue 
advantage of the East and the detriment of the West. 
“ Strange as it has always appeared to me, the peo- 
ple of the West have always allowed this thermal 
element of climate to rest upon a common standard 
for the East and West, where the resultant effects are 
so dissimilar, in that the important factor of dryness 
of the air is entirely overlooked. The West should 
insist upon the publication of the sensible temper- 
ature, that is, what is technically known as the read- 
ing of the wet bulb. We woidd understand then 
why the high thermal conditions, apparently the 
same, do not here cause the cessation of business, 
prostration or death to man or beast, as among our 
Eastern neighbors. The difference between the 
apparent and the sensible heat in this vicinity being 
many degrees, explains our extreme comfort, while 
summer prostration in the East is explained by their 
slight range of difference. The very highest official 
record of heat at Yuma, Ariz., is 118 degrees, but the 
sensible heat at the time—that in the reading of the 
wet bulb—was 32 lower or 86 degrees. In the East- 
ern States 86 degrees of sensible heat is not uncom- 
mon when the thermometer stands in the nineties.” 
Besides the quality of stimulation which is associ- 
ated with variability, there is an important consid- 
eration in the purifying of the atmosphere which 
variability indicates. This happens through the 
alternate expansion of the air by heat and its contrac- 
tion by cold together with the nightly chilling and 
sometimes freezing, which regularly render it inimical 
to germ life. The purity of the atmosphere which is 
represented by warm, moist and equable climates, is 
not to be compared with that purity which is repre- 22 
sented by the opposite attributes. The first is where 
the temperature keeps within the limits of the 
microbe’s needs, where sound as well as heat is 
smothered within a short distance and the sun’s rays 
give a dusky red glow. The second, indicating a 
comparative absence of germs, is where exposed meat 
can cure and not spoil, where distant objects appear 
near and where the unobstructed rays of the sun give 
nearly as white a light as an electric lamp does. 
Diathermancy 'preferred to dense, moist or smoky 
atmosphere.—This diathermancy is the clearness or 
transparency of the air, which is a decided indication 
of its purity. It is with the atmosphere as with water. 
The larger the lake, with perfectly clear water through 
which one can see to a great depth, the better is the 
evidence of purity. So a large area, having through- 
out a similar atmosphere, through which one can see 
to most remarkable distances, must indicate as its 
coldness, rarefaction and dryness do, that the purity 
is approaching the absolute. This increasing purity 
of atmosphere, the absence of dust, smoke or moisture 
with its attendant infusoria is a decided feature of 
elevation, because with each rise of 1000 feet an 
equivalent stratum of air has been left below and, 
according to Professor Tyndall, each higher succes- 
sive stratum contains less and less of infusoria. Pro- 
fessor Miquel of the Observatoire de Montsouris, near 
Paris, has achieved a result in the analysis of the air 
which is very interesting in this connection.1 
Miquel found the following numbers of bacteria in 
ten cubic meters of air taken as nearly as possible at 
the same time at the respective places: At an eleva- 
tion from 2000 to 4000 meters, none; on the Lake of 
Thun (560 meters), 8; near the Hotel Bellevue, Thun, 
85; in a room of the Hotel Bellevue, Thun, 600; in 
the Park of Montsouris (near Paris), 7600; in Paris 
itself (Rue de Rivoli), 55,000. These figures are cer- 
tainly suggestive of the fact that atmospheric purity 
keeps pace with diathermancy. A rule for the average 
i “Chronic Pulmonary Phthisis,” by Hermann Weber. 23 
change in diathermancy, for each rise in elevation, 
was devised by the writer in 1876 from consecutive 
observations of the sun temperature at 2 p.m. and at 
different elevations2: For each rise of about 235 feet 
there is one degree greater difference in temperature 
betuoeen sun and shade at 2p.m., as shown by metallic 
thermometers. 
The distribution of atmospheric moisture closely 
coincides with that of the soils. The dry soils, the 
rocky and sandy portions of mountainous configuration, 
and the dry sandy loams, with rapid absorption of air 
vapor and radiation of heat, nearly represent the dry 
climates. Per contra, the clay soils and marshes of 
level sections, with their moist cold and the easy 
solution of organic substances, are closely associated 
with the moistest atmospheres, excepting where humid 
currents come from over large bodies of water. This 
correspondence with reference to broad areas becomes 
strong proof of the utility of our preferable combina- 
tion of climatic attributes. 
A mountainous country, aside from the benefit of 
elevation, has many advantages over a level region. 
Chief among these are the quick drainage, which 
allows of no detention of stagnant water, the greater 
surface of the earth exposed to absorb atmospheric 
moisture, the many faces of rocks, etc., favoring radia- 
tion of heat and reflection of light, the element of 
stimulation, both atmospheric and electric, the con- 
trolling of severe winds, the variations of scenery, 
temperature and exposure afforded and the facility 
with which one can indulge in climbing hills and in 
pleasurable out-door activities. When these advan- 
tages are compared wTith the moisture-retaining prop- 
erties, the sameness, the “siroccos,” the trade winds, 
and the “northers” of level regions, one easily chooses 
between them. 
The changes in the atmosphere accompanying the 
variability of temperature of mountainous places are 
2 Rooky Mountain Health Resorts. 24 
decidedly electric. There is an increase of electric 
tension and there is an easier and more frequent 
interchange between the positive electricity of the 
dry air and the negative quality of the ground and 
clouds. The condition is very stimulating. This 
quality in high altitudes is associated with light 
showers, especially in summer time when they are 
most needed to clear the atmosphere. The simultaneous 
whirl of a light wind, often seen at a great altitude, 
purifies by its substitution of an unused and fresh sup- 
ply of air for that which may be impure. Where people 
crowd together in large numbers, the daily freezing of 
the air is the only sufficient substitute for a mild 
wind. We thus arrive at the conclusion that in densely 
settled sections continuous stillness of the atmosphere 
is only to be preferred in the freezing weather of win- 
ter. The warmer the atmosphere the more air move- 
ment is desirable. 
It is where there is a total absence of land influence, 
as at sea and on islands far out, or on dry, sandy 
coasts, with favorable sea winds prevailing, that low 
altitudes may best be substituted for high ones. The 
malarial and organic emanations from the soil, which 
are a fruitful source of increased mortality from con- 
sumption (Buchanan and Bowditch), are thus ex- 
cluded from the climatic calculation. The aseptic 
condition of the atmosphere out at sea (Miquel), its 
quality of stimulation, and the tonic effect of the 
change, including the improvement of appetite and 
digestion, are all akin to the best effects of high 
altitudes, though the elimination of septic germs is 
less perfectly performed. 
The evidence of experience.—This is in harmony 
with these favorable climatic attributes. One diffi- 
culty is our inability to make use of statistics of low 
lands which are fair for comparison with those which 
have been tabulated for high altitude stations. We 
have to explain in this connection, that the term 
“cured” should be qualified as meaning a more or 
less permanent arrest of disease, and that the records 25 
given, embrace only those treated during a limited 
period by any of the observers. 
The tabulated records at hand of careful and trust- 
worthy physicians, show the favorable results in both 
the Swiss Alps and in Colorado (4500 feet and up- 
ward) to be as follows: For all stages of the disease, 
of 247 consumptives treated in the Swiss Alps, 38 per 
cent, were “cured” among 72 per cent, benefited. In 
Colorado 402 cases, 35 per cent, are recorded as 
“cured” among 75 per cent, benefited. This slight 
difference in percentage should be explained as quite 
natural considering the variable times of treatment, 
and the diverse interpretations by different physicians 
of the extent of the disease and of the relief afforded. 
Colorado really has many advantages over Switzer- 
land as an all the year round resort, and also in the 
facility afforded to graduate the altitude to the season 
of the year. 
In conclusion it is apparent that the element of 
altitude is inseparable from the best climate for 
chronic pulmonary diseases. The natural question 
then follows: What is the limit up to which this com- 
bination of qualities can be carried that the best 
results may be obtained? This is a question of indi- 
vidual adaptability which has to be settled by the 
attending or consulting physician. The best method of 
settlement is to determine what conditions or diseases 
are suitable for the extreme or the preferrable com- 
bination of attributes, and then arrive at modifications 
or rejections of the high climate cure by a system of 
exclusion. This method is that always advised by the 
writer (Rocky Mountain Health Resorts), and is sec- 
onded by the extended experience of Jaccoud as given 
in his work on “The Treatment of Phthisis.” Jac- 
coud’s conclusions are in the main correct, but it must 
be borne in mind that they, like those of Tucker Wise, 
Hermann Weber, and most of C. Theodore William’s 
records, pertain to a more northern latitude than we 
reason about in the United States. In the Engadine, 
in Switzerland, the limit of timber growth is at or 26 
below 8000 feet, an elevation compared with a similar 
limit at or above 11,000 feet in Colorado. Here the 
gradual rise, the distance from the sea, and the peculiar 
protection of mountain ranges make the change from 
low levels less severe. Also, in America, we have an 
increased advantage over most of European high 
climates in that we keep up the curative effect by 
suitable increase of altitude in summer. Instead, 
they are compelled, as at Davos, St. Moritz, etc., to 
give up the chosen climate treatment during the warm 
weather. The plan of deciding if the preferable 
climate can be made use of in a given case by exclu- 
sion because of negative conditions will not be readily 
accepted by the over-zealous advocates of low climates. 
This is, perhaps, because generally speaking, the more 
reasons there are for exclusion from the better high 
climate, the less likelihood is there for an ultimate 
recovery. Besides, it is not always easy to decide 
what change of climate a given patient can have, 
because of the varying conditions to be weighed, both 
as to the patient and as to the climate. We have to 
summarize by saying that the preferable climate for 
the great majority of consumptives in the United 
States varies, according to the case, between over 2000 
feet elevation in the north in winter, and 10,000 feet 
as a possible extreme in the southern portion in sum- 
mer. As to patients, not omitting social and eco- 
nomic bearings, they vary also, all the way from those 
cases that are hopeless to those that are to prove cura- 
able. There must then, of necessity, be many very 
delicate and intricate questions to be decided by the 
attending or consulting physician Of course, then, 
any rule of procedure must be susceptible of much 
variation. The physician who takes the most factors 
into account and weighs them best will be most suc- 
cessful in the management of each individual case. 
With this broad proviso we will state some general 
reasons why a given invalid may not go to an other- 
wise preferable high climate, and thus emphasize 
those who may.. Assuming that he can relinquish 27 
home and business cures and is financially able to 
remain from four months to two years away from 
home, or better, perhaps, make a permanent residence 
where he recovers, then the following are what wo 
may consider as possible contraindications to a climate 
above 5000 feet elevation, such as that along the 
eastern base of the Rocky Mountains from Wyoming 
through Colorado into New Mexico and northern 
Arizona. 
1. The coldest season of the year, intensifying the 
effect of altitude too much for very delicate and sen- 
sitive persons, corning from much warmer climates. 
2. Advanced age of the individual, rendering accli- 
matization difficult; “senile phthisis” and the fact 
that the patients are too old and feeble to exercise 
out of doors. 
3. A very excitable nervous temperament, aggravat- 
ing the stimulation of the high climate, producing 
irritability, and possibly wakefulness in a few extreme 
cases. 
4. The state of some women, because of a greater 
susceptibility and lesser adaptability to the change 
and to out door life than men have. 
5. Valvular heart lesions, with rapid action of the 
heart, especially with the previous exceptions. Dis- 
eases of the great vessels, such as aneurysm. 
f>. Marked and extensive emphysema, pneumo- 
thorax, and hydro-pneumothorax. 
7. Active pneumonia and existing hemoptysis. If 
the pneumonia or the hemorrhage is recent, the con- 
traindication amounts to little; if remote, such cases 
are usually favorable. If there is reason for doubt 
in any such hemorrhagic or inflammatory case, a grad- 
ual rise in elevation should be advised. 
8. Very high body temperature, whether it is rather 
constant, as in some inflammatory states or in catarrhal 
extensions beyond a tubercular center in the lung, or 
whether it is regularly vacillating, i.e., daily subnor- 
mal in the morning, and regularly up to 103 degrees 
POSSIBLE CONTRAINDICATIONS. 28 
or more later in tlie day, especially in so-called catarrhal 
phthisis and in laryngeal tuberculosis (unfavorable 
cases anywhere). 
9. Too extensive involvement of lung tissue in dis- 
eased action, i.e., so that the healthy spirometric rec- 
ord is more than one-half abridged. 
“ Phthisis with double cavities, with or without 
pyrexia; cases of phthisis when the pulmonary area 
at low levels hardly suffices for respiratory purposes ” 
(C. T. Williams). 
10. The active stage of lung softening, if accompa- 
nied by daily fever, or in one of a decided hemorrhagic 
diathesis. “ Quick consumption ” with or without 
intestinal ulceration or albuminuria (without predju- 
dicing such a case if the acute symptoms are abated). 
A proper estimate and consideration of these ten 
possible modifiers of the high altitude prescription 
tend to give the physician confidence of success in 
sending to well chosen elevated regions, such as the 
plains and foothills about Denver, incipient and first- 
stage tubercular pulmonary invalids, particularly if 
they are hemorrhagic or inflammatory cases without 
high fever, persons not too old and of fair resisting 
powers, and those with advanced or third-stage disease 
with a unilateral cavity already well protected by a 
conservative fibrosis. 
The time to remain in a climate in which recovery 
seems to have taken place is a more delicate question 
than is generally considered. This is because tuber- 
culosis is apt to be rendered latent by the climatic 
treatment and by nature’s healing plan—the fibroid 
or hardening process. It is often essential not only 
that a patient should reside permanently in the new 
immunity climate he has reached, but that he should 
adopt a new and outdoor active occupation, in order 
to obtain the best results. In less urgent cases, en- 
couraged by the absence of all physical signs of dis- 
ease during a year or more, by gain in weight and by 
normal spirometer and manometer records, patients 
may return to their former homes to live with com- 29 
parative safety. Many, however, find themselves 
deceived as to their real condition when they return 
to their old haunts and confined occupations. 
The three principal agencies of relief or cure of tuber- 
culosis thus far discovered, independent of a possible 
specific (some modification of tuberculin) to produce 
immunity, are diet, exercise and climate. These, rightly 
employed, tend to render the disease latent or innocuous 
through the process of fibroid healing in the lung 
tissue. The body resistance is strengthened, but the 
tuberculosis being latent, the individual has the same 
fight to go over again (it may be with a more unfav- 
orable outlook) if he does not accept and act upon 
the lesson of experience. His climate, occupation 
and his habits of life, as to exercise and feeding, must 
thereafter coincide with what he has found to be most 
beneficial in his health seeking journeyings. 
Asthma and hay fever.—The name “hay fever” is 
a misnomer as applied to the breathing disability of 
many people, since the growth of hay has to do with 
only a small proportion of these cases. The causes 
are various, and whether having to do with the flower- 
ing of apple blossoms, the pollen of corn or of the 
Roman wormwood, nervous shock or to the dustiness 
of “dog-days,” the fact remains that four-fifths of 
these so-called “hay fever” subjects are prone to 
cough and asthma. The nature of the affection is, 
like asthma, of nervous origin, and the best mode of 
relief in many cases is, much like that of asthma, to 
get out of the region of excessive vegetation into the 
rarefied air of the mountains. 
One of the most troublesome complications in some 
of these “ hay fever ” cases is the asthma. The 
author gives it as his opinion, based upon an extended 
experience in Colorado, that there is no cure for pure 
and simple asthma eqiml to a resort to a well chosen 
high altitude such as the cool, dry and sunny inland 
plains and lower mountains of Colorado. 
There is a prevalent misconception about this ques- 
tion of asthma, which explains the non-recognition 30 
of the above truth, by many sufferers or by their 
medical advisers. It is not well enough understood 
what emphysema is, that it is not asthma, but rather 
the result of it. Asthma is a nervous disease. It 
produces the undue spasm or contraction of the cir- 
cular muscular fibers of the smaller bronchial tubes, 
and the consequent hindrance to the air-circulation, 
or free inspiration. On the contrary, emphysema is 
a mechanical state of the vesicular portions of the 
lungs which complicates such conditions as asthma, 
whooping-cough, bronchiectasis (dilated tubes) and 
bronchitis, until there exists a more or less permanent 
disability of the air-cells, leading to their over-dis- 
tension and the loss of their natural elasticity. Hence 
the difficulty and incompleteness of expiration. The 
one condition — asthma — hindering inspiration, is 
helped and sometimes immediately relieved by eleva- 
tion; while the other—emphysema—hindering expira- 
tion, is sometimes made worse by the same element of 
air rarefaction. This is because the affected air-cells 
and distended bronchial tubes in emphysema are still 
more crowded with air, especially under any physical 
exertion, by the necessity to breathe more air in the 
mountains, in order'to get the required amount of 
oxygen. Therefore, those of the “hay fever” class 
who have, or are prone to asthma, might be expected to 
find much relief, or a cure for the time being, in the 
high altitudes of the interior of Colorado. Pure and 
simple asthma usually meets at Denver, or in the 
hills to the west, with an elevation, aided by the 
sparcity of vegetable growths and the pollen-produc- 
ing plants, which prevents the spasmodic contraction 
of the bronchial tubes, and the cure for the time of 
sojourn is established. 
Malaria.—The aid of the high climate in elimina- 
ting malarial pcison from the system of a person so 
charged, is a subject worthy of notice. The suspicion 
that malaria, like la grippe, bears a near relation to 
tuberculosis is firmly fixed in the minds of some phy- 
sicians. So the opposite climatic conditions to those 31 
which produce the malarial complications are the 
more trusted to wear out these evils. It is rather a 
continuation of this eliminating process that the chills, 
when one comes up here with them, are sometimes 
aggravated at first. The general result, however, is 
good. The elimination of the malarial poison, which 
many sojourners in Colorado from Texas and the 
Mississippi Valley have shown by their happy expe- 
riences does take place, constitutes the removal of one 
of the most fruitful sources of pulmonary consump- 
tion. Thus the fascination is explained which the 
high altitude climate has for many people, who have 
left behind them the “epidemic shades” of these low 
sections. 
In sending invalids to Colorado, a correct diagnosis 
is an essential condition of success; for, the physician 
of much experience in high altitude resorts has to 
acknowledge that too many failures or limited recov- 
eries can be accounted for by a previous neglect to 
duly estimate a lung disease as farther advanced than 
it had been announced, or by a failure to sufficiently 
recognize the damaging association of “mixed infec- 
tions,” such, for instance, as arise from other blood 
taints than tuberculosis, or from the non-recognition 
of the co-existent or causative effect of fermenting 
blood states, due perhaps to dyspepsia, or to the non- 
elimination of effete material, as in amenorrhea, with 
or without constipation. 
Allowing patients to go to high altitudes as a 
dernier ressort, who have not a 5 per cent, chance of 
living six months anywhere, is strongly deprecated. 
It should be remembered that every rule lias its excep- 
tions, and the stated contraindications named may 
perhaps be neutralized by favorable circumstances, 
such as the best time of year for the change, previous 
experience of the individual in high climates or the 
combination of compensating conditions in the same 
patient. 
The S(‘asons.—These natural divisions of climate 
necessarily influence the journeyings of invalids, the 32 
time of going as well as the choice of the destination. 
The lack of space here to introduce them, and the 
advantage of the medical advisers to have on hand an 
ever ready reference to all important seasonal weather 
records, leads the writer to refer for all these data to 
his seasonal humidity, temperature, rain, wind and 
cloudiness charts. 
The question of the season of the year is one of no 
small importance, notwithstanding the general truth 
that the best time for a person to go is when he has to, 
because of the beginning of lung trouble and not as 
a last chance. For one who really needs the change, 
there is no better time than the present. The season 
of the year does not produce so much difference in the 
indications for a given invalid’s hastening away as 
does the advance of the disease from incipiency, or 
the first stage, to the ominous second stage, when the 
lung is “going to pieces.” While the summer is by 
far the most satisfactory season to be in our moun- 
tains, and the autumn is a good season to get accli- 
mated to a given high altitude before cold weather 
comes on, yet many maintain that the best results 
obtained by those suited to the rarefied air cure, are 
secured in the winter season. On the other hand, 
others not so well suited, such as neurotic persons, 
those unable to exercise outdoors because of advance 
of disease or extensive fibrosis leading to marked 
dyspnoea, or those with too sensitive mucous mem- 
branes to stand the cold, stimulating and dry out-of- 
door air, may do well to modify the effects by going 
first, via Texas perhaps, to southern New Mexico, 
Arizona or California, during the months from Novem- 
ber to March, intending to reach Colorado afterward. 
To this conclusion then we have arrived, namely, 
that for the great majority of cases of consumption 
this adaptation will be most fully secured in the dry, 
cool, rarefied, sunny, clear and pure, though variable, 
atmosphere of a well chosen high altitude, such as is 
fittingly represented by the region along the eastern 
base of the Rocky Mountains.