496 
filtrate and it was found that the germinating power of the tubercle 
bacilli lasted one hundred and four days, but after one hundred and 
eleven days they were incapable of conveying the disease to guinea 
pigs by inoculation. Harrison concluded that these experiments jus- 
tify the statement that Emmentaler cheese may be eaten with safety, 
as the period of ripening is much longer than the period during which 
the bacilli become innocuous. Cheddar cheese is seldom eaten under 
four months from time of manufacture and during this period the 
tubercle bacilli lose their vitality. Not withstanding this, however, 
the writer recommended the pasteurization of the milk in order to 
make the cheese absolutely safe. 
In manufacturing margarine, the method commonly employed is 
to subject the finely comminuted fat to a temperature not to exceed 
50° C. for 1J hours. Sour milk is then added and the whole mass 
is thoroughly mixed; dairy butter is next added and a certain pro- 
portion of oils (cotton, palm, cocoanut, etc.). Enough of one or 
more of these oils is added to lower the melting point to that of dairy 
butter. Hence it will be seen that artificial butter thus made may 
be infected in three w~ays: First, from the fat secured from the origi- 
nal cattle, as tubercle bacilli will withstand a temperature of 50° C. 
for some hours; second, from the butter or soured milk that has 
been added; and, third, from contamination during the course of its 
manufacture. Morgenroth made examinations of 20 samples of ole- 
omargarine, purchased in the open market, and proved the presence 
of virulent tubercle bacilli in 9 of the specimens. 
Other products which occasionally are consumed by people, but 
are used more extensively as food for five stock, will also serve to 
convey tubercle bacilli from infected milk to those that are allowed 
to consume them. Thus, whey from cheese factories and butter- 
milk and separated mil k from public creameries are all offenders in 
this respect and have been incriminated, especially in the feeding of 
hogs and calves. 
VALUE OF THE TUBERCULIN TEST. 
The symptoms of tuberculosis in cattle are not sufficiently promi- 
nent except in advanced stages or when superficially located to ena- 
ble one to diagnose this disease by the ordinary methods of physical 
examination. And cattle may, without showing any clinical symp- 
toms, be in such a stage of tuberculosis as to render them capable of 
spreading disease. Indeed an animal may be fat and sleek, eat and 
milk well, have a bright, glossy coat, and be apparently in the pink 
of condition, and still be passing tubercle bacilli through the feces 
or by an occasional cough, and thus endanger all the healthy cattle 
in the herd. Consequently, such adventitious aids to diagnosis as 
