IN SUSCEPTIBLE ANIMALS. 505 
it retains its blue color in presence of this bacillus, while the bacillus 
previously described causes it to change to red. Neither phenol 
nor indol is produced in solutions containing peptone (Bunzl-Federn) 
—another distinguishing character from the Bacillus septiceemize 
hemorrhagice. This bacillus may be cultivated in slightly acid 
media, which after a time acquire an alkaline reaction. 
In Smith’s experiments this bacillus was found to resist desicca- 
tion from nine days to several months, according to the thickness of 
the layer dried upon the cover glass; bacilli from an agar culture in 
some experiments failed to grow after seventeen days, and in others 
still gave cultures after four months. Bouillon cultures are steril- 
ized in four minutes by a temperature of 70° C., in fifteen minutes 
by 58° C., and in one hour by 54° C. (Smith). Novy has isolated 
from cultures of the hog-cholera bacillus a toxic basic substance 
which he calls susotoxin, This was obtained by Brieger’s method ; 
it is a yellowish-brown, syrup-like liquid, which, when injected into 
rats in doses of 0.125 to 0.25 cubic centimetre, causes their death in 
less than thirty-six hours. He also obtained by precipitation with 
absolute alcohol, from cultures concentrated in a vacuum at 36° C., 
a toxalbumin which when dried was in the form of a white powder 
easily soluble in water. Rats died in three or four hours after re- 
ceiving subcutaneously a dose of 0.1 to 0.5 gramme. 
Pathogenesis.—Pathogenic for swine, rabbits, guinea-pigs, mice, 
and pigeons. 
Tn certain parts of the United States the disease known as “‘ hog 
cholera” frequently prevails among swine asa fatal epidemic. It 
may occur as an acute and quickly fatal septiczemia, or in a more 
chronic form lasting from two to four weeks or even longer. In 
the acute form death may occur within twenty-four hours, and hem- 
orrhagic extravasations are found upon the mucous and serous 
membranes and in the parenchyma of the lungs, kidneys, and lym- 
phatic glands. The spleen is greatly enlarged, soft, and dark in 
color. In the chronic form of the disease the most notable changes 
are found in the alimentary canal. These are most constant and 
characteristic in the cecum and colon, which may be studded with 
spherical, hard, necrotic masses or extensive diphtheritic patches. 
According to Smith, the hemorrhagic and necrotic form of the dis- 
ease may exist at the same time in different animals of the same 
herd. The bacilli are found in all of the organs, and especially in 
the spleen, where they are associated in irregular colonies similar 
to those of the typhoid bacillus. Smith has demonstrated their pre- 
sence in urine taken from the bladder immediately after the death 
of the animal, and states that the kidneys are almost always in- 
