124 
FRANK S. BILLINGS. 
for one ever since, but in vain), I shall use the rubber tubing 
again, as it rendered me satisfactory services in ligating other 
tumors, among them two on the tail (melanotic), one on the hock 
joint, and one on the scrotum. All healed off without interrup¬ 
tion. In short, this method is, in my opinion, preferable to ex¬ 
tirpation. 
THE ETIOLOGICAL MOMENT IN AMERICAN SWINE PLAGUE. 
REPORT OF THE WORK DONE IN THE LABORATORY OF THE 
STATE UNIVERSITY OF NEBRASKA FOR THE EXPERIMEN¬ 
TAL STUDY OF CONTAGIOUS AND INFECTIOUS ANIMAL 
DISEASES. 
{Continued from page 66.) 
THE MOST PRACTICAL METHOD OF OBTAINING PURE CULTIVATION 
FROM THE TISSUES OF DISEASED ANIMALS. 
Pathological exudations, such as used by Dr. Detmers, serve 
very well to inoculate animals with, either to test the character of 
a disease, and if contagious or infectious, to obtain, in most cases, 
absolutely pure cultivations of the germ by inoculating some ster¬ 
ilized gelatinous medium with the substance of some solid organ, 
with every precaution against contamination by adventitious 
germs. At the same time some small animal should also be 
inoculated from the same organs. When possible, the animal 
from which such material is taken should be killed rather than 
allowed to die. The cultures soon grow. They are examined 
and the pure ones used for the successive cultivation of any de¬ 
sired number of generations. At the same time the growth of 
the organism may also be tested in and upon any other media 
than the one first used. For primary cultivation agar agar and 
sterilized blood serum are most advisable, as they permit the use 
of the thermostat. In the meantime, the animals inoculated be¬ 
come ill and may be killed and tubes inoculated from their blood 
and tissues under due precautions; the resulting developments 
are then to be compared with those first obtained by microscopical 
examination and their deportment in the various media of culti¬ 
vation. By this method one is enabled to get the organism in a 
