BACTERIAL POISONS IN MILK AND MILK PRODUCTS, 
BY 
PROF. V. C. VAUGHAN, M. D, 
DIRECTOR OF STATE LABORATORY OF HYGIENE, ANN ARBOR, MICHIGAN. 
fRepiam: No.m{ BACTERIAL POISONS IN MILK AND MILK PRODUCTS. 
BY PROF. V. C. VAUGHAN, M. D., DIRECTOR OF STATE LABORATORY OF 
HYGIENE, ANN ARBOR, MICHIGAN. 
[ Reprinted from the Proceedings of Third Annual Conference of Health Officers in Michigan, held at 
Ann Arbor, July 16 and 17,1896.] 
[Reprint No. 468.J 
Mr. President, Gentlemen—I am not going to read a paper today, 
but am going to give you a talk which I hope will be practical. I have 
made the statement elsewhere that milk is one of the deadly drinks. I 
want to tell you this afternoon wherein and for what reasons it is deadly. 
Dr. Baker will give us a paper soon on Infantile Mortality, but I think lie 
will pardon me for making the statement just now that one-fourth of all 
the children born to the civilized world die before they reach five years of 
age, and that about one-half of these deaths are due to intestinal disturb- 
ances, and these intestinal disturbances are cases of milk poisoning. 
Therefore, about one-eighth of all the children born into this world die 
before they are five years of age from the effects of impure milk. Now am 
I not right when I say that milk is a deadly drink? In making this state- 
ment I do not take into consideration at all the large number—I do not 
know how may—of persons over five years of age who drink milk con- 
taining germs, such as the germ of tuberculosis, for instance. 
We may divide the germs that are found in milk into two classes: (1) 
Those that are in the milk when it comes from the udder of the cow, and 
(2) those that find their wav into the milk after it is drawn. The per- 
fectly healthy cow’s milk is germ free. I have about the laboratory here 
somewhere—I might have looked up the tubes—samples of milk that I BACTERIAL POISONS IN MILK AND MILK PRODUCTS, 
21 
drew from a cow in 1888. I sterilized the tubes, then went out to milk the 
cow, carrying with me an alcohol lamp and a solution of bichloride of 
mercury, and I disinfected the exterior of the udder carefully, then in the 
alcohol lamp I heated one end of each tube and with a pair of forceps 
broke off that end of the tube. As soon as it was sufficiently cool I intro- 
duced it into the udder and allowed it to fill with milk, and then immedi- 
ately sealed that end of the tube again, the other end remaining sealed 
all the while. The last time I looked at these tubes—I say they were 
drawn in 1888, the last time I looked at them was in 1894, when the milk 
had not soured, it had not coagulated, it was just as it was at first with 
the layer of cream above and the unsoured milk below. 
Now what is said of the milk of the cow is true of the milk of the 
healthy mother. It is practically germ free. Absolutely germ free if the 
mother is in good health. This is the chief reason why children fed exclu- 
sively from the breast of the mother do not have these diarrhoea! disturb- 
ances of which I spoke a moment ago. They are practically unknown 
among those children taking their food exclusively from the breast of 
the healthy mother. It is not because the child cannot digest the milk of 
the cow that so many artificially fed children die, it is not because there 
are slight chemical differences between the milk of the cow and the milk 
of woman, it is because in the artificially fed child the milk becomes pois- 
onous. That is it. 
Now remember I have divided the germs into those in the milk when 
drawn and those which find their way into the milk after it has been 
drawn or in the process of milking. For the present at least I am not 
going to say anything about the first class of germs that I have mentioned 
here, those that are in the milk in the cow. I am going to discuss those 
germs and those bacterial poisons which arise from the contamination of 
the milk during the milking or after the milking. 
We may divide these germs again into specific germs and non-specific 
germs. For instance, if the milkman dilutes his milk with water con- 
taining typhoid germs, then that milk supply may spread typhoid fever. 
In that case a specific germ, a germ capable of producing a definite dis- 
ease has been added to the mi’k, and the milk becomes poisonous for this 
reason. Dr. Christian, of Wyandotte, sent us some years ago a sample of 
water from the well of a milk man, and some of the milk from the cans, 
of the milk man, and he told us that the typhoid fever in Wyandotte fol- 
lowed this milk man’s wagon, that typhoid fever was in nearly every 
family taking milk from this man, and that there were no other cases in 
the town. We found the same germ in the water and in the milk. There 
was evidently some connection,directly or indirectly, probably indirectly, 
between the udder of that man’s cows and the well. This is a case of 
specific infection of the milk after it is drawn. In addition to the typhoid 
germ we might have specific infection of the milk with diphtheria, pos- 
sibly with scarlet fever, possibly with small-pox, or with any of the spe- 
cific diseases. The germs of these specific diseases may get into the milk 
after it is drawn, and then the milk might be used as a vehicle for spread- 
ing any specific disease. But I am not going to discuss that class of 
germs found in milk. I am going to tell you about the non-specific germs, 
the toxicogenic germs as we call them here, the poison-producing germs, 
that do not produce typhoid fever, nor scarlet fever, nor measles, nor 
whooping-cough, but which do produce poisons. 22 
CONFERENCE OF HEALTH OFFICERS IN MICHIGAN, 1896. 
Now Dr. Novy has in his very admirable paper told you all about or a 
great deal about the toxins, and told it well. I want to sum up one of his 
statements td show that the difference between the germ and its toxin 
is one of degree and not one of kind. In the germ we have a poison -which 
is capable of multiplying. We have a living, growing poison, it is a 
poison, a chemical poison, but a growing poison, one capable under suita- 
ble conditions of indefinite multiplication. In the toxin we have the 
same poison exactly, just as deadly if we could get it in the same amount, 
but it is no longer capable of multiplying, and it is a difference in degree 
rather than kind. The germ is the living poison; the toxin is the dead 
jjoison, and by the distinction here between life and death I mean that the 
one is capable of multiplication, and the other is not capable of multipli- 
cation. That is all. Otherwise they are the same. 
Now there are a great many germs, no man knows how many there 
are, that grow readily in milk and produce poisons. A number of years 
ago two acquaintances and friends of mine started out to find the specific 
germs that were supposed to grow in milk and produce the poisons caus- 
ing the summer diarrhoeas of infancy. These men were Dr. Booker of 
Baltimore and Dr. Escherickof Munich. Booker isolated as many as thirty 
germs found in the stools and intestines of children suffering from the 
summer diarrhoea, many of which produced poisons in milk, and Escher- 
ick isolated quite as many more. How many remain undiscovered as yet, 
no man can tell. 
Now I want to make this talk just as practical as it is possible to make 
it, and I want to give the conditions under which milk must be drawn 
and kept in order to prevent its being poisonous. Of course we must 
have healthy cows to start with. When we had the Convention here two 
years ago I introduced a resolution and it was approved by the Confer- 
ence, asking the legislature to pass an enactment forbidding the sale of 
milk by any save those licensed to sell it, and that these licenses should 
be granted only after an inspection or test of the milk by the Sanitary 
Live Stock Commission. 
We should have healthy animals to start with, and then they should 
be properly fed and stabled. The udders of the cows should be washed 
before the milking, and what is of quite as much importance the hands of 
the milker should be washed occasionally as well. The receptacle into 
which the milk is drawn should be washed and should be sterilized. After 
the milk has been drawn from washed udders with clean hands into steri- 
lized Vessels or into clean vessels—at least, I do not know that it is 
necessary to sterilize them if they are clean,—then the milk must be 
rapidly cooled. These poison-producing germs do not grow at a tempera- 
ture below 50° Fah. That is one thing we know about them. The milk 
must be lowered to that temperature or lower as quickly as possible. 
Now let me say right here parenthetically that it has been known of 
course from time immemorial that the great and appalling death rate 
among children grows in the summer time. The British Medical Associa- 
tion, the American Medical Association, the Association of German 
Physicians, and other learned bodies had appointed committees 
which had made report after report to ascertain why it was 
that these diarrhoeas existed in the summer time and not 
in the winter time, and every available reason for it has been given. Phv- BACTERIAL POISONS IN MILK AND MILK PRODUCTS. 
23 
sicians tried to find cause for the infantile diarrhoeas in the sun spots, 
in the position of the moon as to whether it hung high or low, and I have 
honestly heard a paper read before the International Medical Associa- 
tion when it met in Washington in 1887 in which it was suggested that 
the infantile diarrhoeas were in part at least, and in a large part, caused 
by the use of baby carriages. The argument the man gave was unanswer- 
able. He said that the summer diarrhoeas of infancy had increased fear- 
fully since baby carriages had been introduced. You cannot deny that. 
It is true. Therefore the baby carriages caused the summer diarrhoea. 
This seems too ridiculous. Tne members of the State Board of Health 
will remember a similar argument to show that tomatoes caused cancer. 
I believe some of us answered this argument by saying that umbrellas 
caused cancer, because since umbrellas had been used cancer had 
increased. 
I want to relate to you a little incident which will illustrate the neces- 
sity of taking care of the milk as I have before stated. A little child 
which has been under my care ever since its birth had to be fed artifi- 
cially. I had directed the selection and care of the milk. The father 
bought a cow which was proved to be healthy, the cow was well pastured 
and well stabled, but the milk man was not quite as clean as he should 
have been. The milk fed to the child was sterilized. About two weeks 
ago the child very suddenly developed a fearful diarrhoea, 
and was in a dangerous condition, although it was drink- 
ing this sterilized milk. Upon close inquiry the cause for 
it was found to be this: The milk man came very early in 
the morning, the exact hour depending somewhat upon his own pleasure. 
He sometimes came about five o’clock in the morning, drew the milk and 
placed it in the kitchen, where it stood until the girl was ready to attend 
to it. It stood there from five o’clock until eight sometimes before the 
girl got around to it to put the milk in the ice chest, and there was enough 
chemical poison produced in the milk during the three hours to poison 
the child. The milk was then taken and sterilized and fed to the child. 
We found in this milk a germ which undoubtedly came from the feces of 
the cow, some of the fecal matter getting in or blowing in when the milk- 
ing was being done, and within the three hours from five to eight o’clock 
in the morning enough poison generated in the milk to jeopardize the life 
of that child. When the milk was sterilized afterwards the germs were 
killed but the poisons were not destroyed. Of course if the germs had not 
been killed the child probably would have died. Illustrations of this 
kind I might multiply quite indefinitely. 
Possibly some of you remember that in the first ice cream in which 
we found the poison tyrotoxicon that the poison originated in practically 
the same way. It occurred in the village of Lawton, in the western part 
of this State, where the milk was drawn from healthy cows, was brought 
into the village, divided into two portions, one portion was flavored with 
lemon, was frozen immediately and served at a church festival and was 
not poisonous; the other portion was flavored with vanilla, was allowed 
to stand in a very filthy room for three or four hours before it was frozen, 
then it was frozen and served. A teaspoonful of that ice cream was suffi- 
cient to produce nausea and vomiting in an adult. Of course they said in 
this case that the poison was in the vanilla, because one cream Was CONFERENCE OF HEALTH OFFICERS IN MICHIGAN, 1896. 
flavored with lemon and the other with vanilla, and the lemon cream did 
not hurt anyone. Fortunately there was some of the vanilla flavoring 
left, and Dr. and I after drinking it came to the conclusion that it 
did not produce any injurious effect whatever. Another very striking 
illustration was that which occurred at Long Branch, where the milk was 
drawn at the very unusual hours of midday and midnight. The milk 
drawn at midnight was cooled and then carted to Long Branch the next 
morning. The milk drawn at midday was immediately carted to the 
village, a distance of eight miles, in the hot month of August, and some 
hundreds of persons were poisoned with it. Here the milk came from 
the same cows, at different times of the day, all the difference being in the 
conditions under which the milk was kept. 
Now the number of germs, as 1 have stated, which may make milk pois- 
onous is quite unlimited. A few of these germs we have isolated. I have 
here one of the milk germs which is capable of changing milk so that it 
becomes very highly poisonous. This germ was obtained first from some 
ice cream which was sent us about a year ago from a village in the north- 
ern part of this State. About 150 people ate of the ice cream and every 
one of them was poisoned to a greater or less extent. Some of the ice 
cream was sent to Mr. Perkins and myself. We went to work with the 
germ and succeeded in isolating it and studying its habits quite thor- 
oughly. We have subsequently found the same germ in cheese. It pro- 
duces practically two poisons, neither one of which have we isolated, 
but one is a basic substance, and the other belongs to the group of toxins 
that Dr. Novy spoke about. This poison, or these combined poisons (both 
seem to have practically the same effect), differ quite markedly from the 
poisons that we have hitherto found in milk. These poisons have a 
more markedly depressing action upon the heart. They cause nausea, 
vomiting, purging as most of the other milk-poisons, but in addition to 
this they cause a very marked depression of the heart. So marked has this 
been that some of the physicians in attendance were struck with the fact, 
and one'of them wrote me: “I have before seen cases of cheese poisoning, 
but I have never seen a case where the heart was so remarkably 
depressed.” The action is very much like that of muscarin, the poison 
which is found in the mushroom. We have studied the conditions under 
which these germs grow. They grow upon almost every vegetable. We 
have grown it on beets, turnips, squash, potatoes, bananas, and almost 
every vegetable and fruit. To my mind this offers an explanation of the 
danger of keeping decayed fruit in the vicinity of milk. I had a case of 
milk poisoning here in town not long ago, and I found that the milkman 
brought the milk in a pail and set it in the cellar. In this cellar were 
decaying turnips, potatoes, etc. I did not have the time to investigate 
these vegetables in order to see if this specific germ was present or not. 
I told you that Dr. Booker had isolated a large number of germs which 
he had found in the evacuations of children. He was kind enough to 
send me some of these germs, and I have obtained the chemical poisons of 
some of them. I found that all of these germs produce toxins, so-called 
proteid or albuminous poisons which when injected into kittens and 
given to young pups produce diarrhoea, exhaustion, and death. There 
are “many interesting things about these poisons, and particularly the 
effe'et they have upon some animals as compared with others, and the BACTERIAL POISONS IN MILK AND MILK PRODUCTS. 
25 
effect they have upon different animals at different ages. It would be 
practically safe for an adult to drink milk that it would be very unsafe 
for a child to drink. We can demonstrate this in the lower animals. 
Quantities of this poison will affect pups and young kittens when ten, 
twenty or thirty times the amount would not affect adult animals of the 
same species. We found also a great difference in the effects upon rats 
and cats. 
I have already formulated elsewhere the rules for taking care of milk. 
I want to say something about sterilizing milk. I am not going to touch 
upon your subject, Prof. Smith, only to say this, that many of the bac- 
terial poisons that are formed in milk are not destroyed by sterilization 
or pasteurization. We must prevent the formation of the poison before 
we sterilize or pasteurize the milk. 
I think these are the main points that I wanted to present to you. If 
there are any questions I shall be glad to answer them. The poisons 
that have been found in milk so far are tyrotoxicon, which is a ptomain 
or basic substance, and the basic substance which have not been isolated, 
and a number of toxins or poisonous albuminous substances, probably 
without limit. We have isolated five or six of the latter in this labora- 
tory. We have separated them from the milk and have poisoned ani- 
mals with them. The importance of the subject will be appreciated by 
the statement that I made in the beginning concerning the large death 
rate in infants. I want to say that since milk has been sterilized and 
since greater care has been given to milk the death rate among children 
from the diarrhoeal disorders have been greatly decreased. I thank you. 
DISCUSSION OF “ BACTERIAL POISONS IN MILK AND MILK PRODUCTS.” 
Dr. Hurd—I would like to ask Dr. Vaughan if a cow might obtain any 
of the specific germs through drinking, and then transmit them to the 
milk? 
Dr. Yauglian—That is a question which I do not think anyone can 
answer at present. A number of experiments have been made, but so far 
the results have been negative. That is, if you have a healthy cow and give 
her typhoid germs or diphtheria germs in water, there is no positive evi- 
dence that that germ really appears in the milk. The tuberculous germ 
may come from the tuberculous cow. 
Dr. Rosenberry—Is sterilization an aid in developing these poisons in 
milk ? 
Dr. Yauglian —I avoided saying anything about sterilization because 
Professor Smith is a better authority upon that subject than I am. How- 
ever, there will be no danger in producing poisons in that way. There is 
one thing that I would like to sav and that is a fact that I do not think is 
generally appreciated. The complete sterilization of milk at any ordin- 
ary temperature is a practical impossibility. That is as it is done for 
children. There are germs that will stand hours of boiling without being 
killed, and these germs are frequently present in milk. Now the point I 
want to make is this: Practically it is just as essential after milk has 
been sterilized for a child that it should be kept in a cool place until the 
child takes it, as it is that it should be sterilized. 26 
CONFERENCE OF HEALTH OFFICERS IN MICHIGAN, 1896. 
Dr. Rosenberry—Are these germs very frequently present? 
Dr. Vaughan—I do not know how frequently, but sometimes they are 
present. Perhaps I made that statement a little too strong. The most 
thorough work that I know of that has been done upon that subject has 
been done by . He found these germs present. I do not remem- 
ber the frequency, but they were present in the milk. 
Prof. Smith—I would like to ask if all of these germs which are pecu- 
liarly resistent to heat do not come in from carelessness or other ways 
which are readily avoidable? 
Dr. Vaughan—Yes, and there is another thing: The people must be 
educated to pay the milk man better prices for his milk. No milk man 
can supply milk as it should be supplied at the prices that are now paid. 
If people would pay half the money for good milk that they pay for the 
worthless and worse than worthless baby foods, we would have a bet- 
ter condition of things. They pay enormous prices for baby foods and 
expect to jew down the milk man. The milk man can not produce milk 
with all the necessary precautions and care at the price. 
Prof. Smith—I would like to ask Dr. Vaughan if he thinks it possible 
that germs would grow in the milk, where the germ was taken into the 
stomach through water or other sources? 
Dr. Vaughan—They would. The germs have been observed to be 
present .and even to grow in sterilized milk, or absolutely pure milk. If 
the germs are there they will grow. But one more thing. The child or 
infant has no business to be drinking water that is not sterilized, or 
taking any other kind of food that is not sterilized. 
Prof. Smith—I tried the same experiment of drawing milk from the 
inner part of the udder of the cow, but never reached the success that 
Dr. Vaughan has. It seems to me simply amazing how long milk will 
keep sweet if drawn in a sterilized flask and the air excluded. We 
have the experiment for students and it assists them to see that the sour- 
ing and curdling of milk are due to germs which gain access after the 
milk leaves the udder of the cow, not after it leaves the teat of the cow, 
but after it leaves the udder of the cow. We find in the teat of the 
cow different germs. We found some germs up there that did not belong 
there, and we do not see how they got there. Instead of washing the 
udder we surround it with one of the patent appliances that keeps the 
manure off. 
Now I am a practical milk man and not a doctor. At some of the 
stables which I have visited in the vicinity of Detroit and its suburb 
Grand Rapids, if you recommended them to wash the udders you would be 
simply, not adding fuel to the fire because water is not a fuel, but you 
would change from the devil to the deep sea. You must not let the 
fecal matter adhere to the udder of the cow. You must use proper 
appliances to keep the cow clean. Just as certain as the milk man keeps 
the cows in such filthy condition that he has to clean the udder, just so 
sure will he be too filthy to trust to wash them. I recommend that he 
brush his cows dry and use the proper stable fixtures to prevent the soil- 
ing of the udders by the dung and urine. 
Dr. Mills—I wish to bring up the subject of legislation in reference to 
this matter of handling milk. T would like to know what the present 
state of the law is in regard to this matter. BACTERIAL POISONS IN MILK AND MILK PRODUCTS. 
27 
Mr. Wells—I know of no recent legislation in regard to the matter so 
far as protecting human beings is concerned. Legislation only goes to 
the extent of protecting animals. 
Mr. Woodman—I desire to ask the; doctor if the presence of the germs 
of tuberculosis in milk can be definitely ascertained by a microscopical 
examination. 
Dr. Vaughan—No, not always. The finding of the germ of tuberculosis 
in milk is not always an easy matter, and if it is not taking too much 
time I would like to bring up one point here to ask Professor Smith about. 
We use the centrifugal machine for isolating germs from urine, milk, 
blood, etc. Now I should not have had any hesitancy had I been asked 
a year ago to swear that cream separated by the centripetal process con- 
tained fewer germs than the milk, but it is not true. The cream will 
contain more germs as a rule than the milk, and sometimes the cream 
will contain more germs than the slime at the bottom of the milk. Now 
the microscopical demonstration of the tuberculosis germ in milk is not 
absolute. The only way that you can be certain about it is to inoculate 
guinea pigs, and of course in order to be absolutely certain you have got to 
inoculate a goodly number of guinea pigs. The tubercle germ does go to 
the bottom better than most of the other germs, but I suppose it is prob- 
ably a little heavier than most of the germs. I am surprised at the 
large number of germs in the cream. 
Mr. Hinds—You were going to ask Professor Smith something. 
Dr. Vaughan—I was going to ask about the number of germs in the 
cream. 
Prof. Smith—We find that the number of germs is vastly greater in the 
cream than in the skimmed milk. Some of you will probably remember 
a case of feeding some hogs in Northern Germany, and how singularly 
fatal the disease was there. I do not know that we have found more 
germs in the cream than we have in the separator slime. 
You said that you would mention two or three facts concerning the 
growth of this germ. I simply have in my notes one, that it grows on 
any kind of vegetable, and hence the danger from decaying vegetables. 
Dr. Vaughan—I must have overlooked the others. It does not grow 
below 25 degrees C.; the maximum growth is 37 degrees C. Another 
thing was the readiness with which the germ is killed. In the sterilizer 
the temperature at 100 degrees C. destroys the germ immediately. 
Mr. Hinds—I desire to say for the information of Dr. Mills who asks 
the question that the Live Stock Sanitary Laws of this State are the 
same that they were when this association met here two years ago. The 
last Legislature made no change whatever in these laws. 
While upon my feet permit me to say that there is a great deal of mis- 
apprehension among milk producers and consumers as to the ability of 
the scientist to determine the presence of tuberculosis in a cow by the 
examination of the milk of the animal, either scientifically or otherwise. 
Dr. Vaughan has answered that proposition in general terms, but the 
practical man will see the difficulty of relying upon that test. For 
instance, if I brought the experienced bacteriologist a sample of milk 
from a cow suffering from tuberculosis generalized, or even specialized 
to an affection of the udder, on some days he might be unable to find 
the bacilli of the disease while on other occasions he might find the 28 
CONFERENCE OF HEALTH OFFICERS IN MICHIGAN, 1896. 
samples from the same cow teeming with the germs of disease. There- 
fore, to have any safety at all from that kind of a test, it would need to 
be kept up almost constantly. There is a common theory even among in- 
telligent people that if they should send a single sample of their milk here 
to the University or to some other bacteriological laboratory, the health 
of their cattle might be at once determined. Of course that understand- 
ing of the matter should be discouraged. 
I also desire to say here and right now in defense of the dairy cow of 
Michigan that she is much less affected with tuberculosis than most 
people are led to believe. Now, as a matter of fact, the laws of this State 
do not contemplate that this commission shall go out and examine any 
domestic animal unless the same or the herd or the flock to which it 
belongs are believed to be affected with some contagious or infectious 
disease of a malignant character. Now, in the course of events, we have 
applied the tuberculin test to cattle from the south line of the State to 
the shores of Lake Superior. In no case has the test been applied except 
where some animal or animals in the herd showed marked indications 
upon physical examination, of being affected with the contagious disease 
called tuberculosis. Among all the animals tested to date, less than 
twelve per cent have showed the presence of the disease by reaction. 
Substantially all of the cattle upon which the tuberculin has reacted have 
been slaughtered and the lesions of the disease have been found upon 
post mortem in every instance. I think I said here in this hall two 
years ago that in my judgment less than one per cent of the cattle stock 
of Michigan was affected with tuberculosis. This was of course a per- 
sonal opinion of my own after extensive opportunities for observation 
and yet I am not disposed to change the estimate after time has giveu 
me much additional information. I do not mean to be understood as 
expressing the opinion that less than one per cent of the milch cows of 
the State are affected with this disease, but that taking the cattle of the 
State as they run, a very small percentage are so affected. In herds that 
have probably been affected for some time and that have been bred 
along lines that did not require the introduction of much new blood, 
we find a very large percentage affected—say fifty or even seventy-five 
per cent responding to the test. Now the law of the survival of the 
fittest takes care that this disease does not spread in many cases. 1 
do not believe that any of these herds would long be so affected with 
tuberculosis if they were turned loose in natural conditions to battle 
with the elements. The very inclemency of the weather would kill off 
Ihe diseased ones before they had seriously spread the malady. Where 
we find the disease flourishing and doing most damage is in herds kept 
in bank barns or other close and warm quarters where it becomes pos- 
sible to keep the diseased animals nurtured and alive too long to the 
infinite damage of the balance of the herd. 
President Wells—We are glad to hear from Mr. Hinds on this subject. 
If there is no more discussion upon the subject of Professor Vaughan's 
talk, we will proceed to the next.