MILK FROM TUBERCULOUS COWS. 
135 
At the end of that time from ten to twenty cover-glass 
preparations were made from various parts of the milk or 
cream. These were stained after Ehrlich’s twenty-four hour 
. method, with fuchsin and methyline blue as a contrast color, 
and then searched with an immersion lens. 
We prepared for examination in the way spoken of above, 
one hundred and seventeen sets of cover glasses from as many 
different samples of milk. Of these specimens three spoiled, 
i. e., turned sour or acid before the examination was complet¬ 
ed, and must be rejected, leaving, therefore, one hundred and 
fourteen samples of milk of which the examination was com¬ 
pleted. These samples were obtained from thirty-six different 
cows, all of them presenting more or less distinct signs of tu¬ 
berculosis of the lungs or elsewhere, but none of them having 
marked signs of disease of the udder of any kind. 
Of these samples of milk there were found seventeen in 
which the bacilli of tuberculosis were distinctly present; that 
is to say, the actual virus was seen in 10+ per cent, of the sam¬ 
ples examined (17:114=10+). These seventeen samples of 
infectious milk came from ten different cows, showing a per 
centage of detected infectiousness of 27.7 per cent. (10 : 36= 
27.7). These results are exceedingly interesting, it seems to 
me, and I confess I am surprised at the size of the percentage 
named. Not because I had not expected to find the bacilli— 
I have been convinced for several years that persistent search 
would show their presence in such cases as those that are here 
recorded—but because the amount of dilution to which the 
organisms must be subjected diminished immensely the chance 
of their being found at all. In no case have they been seen 
in large numbers, but equally in no case has a diagnosis been 
made where there was the slightest doubt of the appearance 
under the microscope. 
The large number of cases in which these organisms have 
been found seem to me to indicate their presence in a still 
greater proportion of cases, if only a sufficiently thorough 
examination of all the milk could be made. This of course is 
out of the question, but the results here given seem to estab¬ 
lish, beyond a doubt, the fact that milk coming from cows 
