624 
F. L. RUSSELL. 
THE DIAGNOSIS OF TUBERCULOSIS, DEALING ESPECIALLY WITH 
THE DOSE OF TUBERCULIN TO BE USED IN TESTING FOR 
TUBERCULOSIS. 
By F. L. Russell, V.S. 
Prof. Veterinary Science Maine Agricultural College, and Experiment Station, Oiono, 
Maine. 
A paper read before the Maine Veterinary Medical Association. 
We find that most of those who have published their exper¬ 
ience in the use of tuberculin have used a much larger dose of 
the drug than we have found necessary, and we wish to bring 
the matter briefly to your attention in a comparison of results as 
it is a matter of general interest and some importance. 
In this country the available tuberculin is mostly from one o^ 
two sources. It is either that prepared in Germany by Dr. 
Libbertz, after Prof. Koch’s formula, or that made in this country 
by the Bureau of Animal Industry at Washington, D. C. This 
latter preparation is a dilute tuberculin of about one tenth the 
strength of the imported drug. Whether the strength of either 
brand is uniform depends upon the care and skill exercised in 
their manufacture, and we will assume that all leasonable caie 
is used as we have no convenient method of testing them. But 
we find that from .2 to .5cc of tuberculin for mature animals is 
generally recommended, while our own experience with a dose 
of .05cc or even .o6cc have been very satisfactory. 
In the New Jersey State College herd the first cow tested 
and one tested at a later date were given -5cc of tuberculin each. 
Thirty-five cows were given .15CC of tuberculin, and three ani¬ 
mals were left untested for want of material. In one case re¬ 
ported in Pennsylvania, .25CC was used with negative»results, 
although an autopsy proved the cow to be tuberculous, and the 
failure was attributed to the smallness of the dose. 
The point I wish to make is that the large dose quite generally 
used has no advantage over a much smaller one, but on the con¬ 
trary, some evident disadvantages. If thirty or forty animals as 
they will be found in a breeding herd of all ages, can be tested 
