GTS 
ROBERT H. WILSON. 
rated over a water bath to one-tenth the original volume. The 
bacteria are removed by passage through filter paper and Berke- 
feld filter. The dose of the concentrated tuberculin is 0.25 of a 
c.c., but owing to the material being of a syrupy consistency and 
the smallness of the dose, it is diluted with 7 to 9 times its bulk 
with 2 weak solution of carbolic acid before being used. This 
is the tuberculin employed in the ordinary subcutaneous test. 
Koch’s Purified Tuberculin consists of the precipitate which 
results from adding several volumes of absolute alcohol to the 
4< Old Tuberculin.” The precipitate is washed and dried. Be¬ 
fore use the dried tuberculin is diluted in water or glycerin. This 
product is used in the ophthalmic test. 
The technique involved in applying the tuberculin subcutane¬ 
ous test is familiar to all and need not be mentioned here. 
The ophthalmic or Calmette test has recently come into use 
more or less extensively. It consists of instilling a small amount 
of the purified tuberculin into the conjunctival sac. A positive 
reaction is characterized by a marked hyperemia of the conjunc¬ 
tiva in from five to ten hours after the application of the tuber¬ 
culin. At present this test is not considered as reliable as the 
subcutaneous. 
The tuberculin test has proven to be of great value in detect¬ 
ing tuberculosis and if it is honestly and intelligently applied can 
be considered sufficiently reliable to be depended upon in every 
case. 
Mallein .—This biological product consists of the glycerinated 
bouillon in which the glanders bacteria have grown and in which 
are contained the products resulting from their development. It 
is prepared and used in a similar manner to tuberculin. In the 
case of a positive reaction with Mallein there is in addition to 
the elevation of temperature more or less local and sometimes 
constitutional disturbances. 
Mallein is recognized as a fairly efficient agent in dealing 
with glanders. If the operator is familiar with all the details 
of the test and capable of interpreting the results, its usefulness 
cannot be doubted. 
