the Brown Institution. 
269 
used to inoculate a guinea-pig, which died on the second day 
after the inoculation, and presented all the post-mortem appear- 
ances of anthrax. Bacilli* were found in the blood from all parts 
of the body ; but they were most abundant in the spleen, which 
appeared swollen and tense. 
From this animal fresh inoculations of others were made, and 
the first series of the cultivation-experiments attested. 
Of the animals inoculated, two guinea-pigs died — one at the 
end of forty hours ; the other was found dead some hours later ; 
and in both bacilli were present in the blood. 
In conducting a series of these inoculations from guinea-pig 
to guinea-pig it was found that they always succumbed to the 
effects of the poison (when active) in from thirty-six to seventy 
hours ; and in only one instance did the animal survive more 
than three days. But in several instances the inoculation failed 
when the animal from which the inoculation material was taken 
had been dead some time, and decomposition had set in. This 
was probably the case in two instances, in which blood taken 
from cattle that died of splenic fever produced no effect on 
guinea-pigs inoculated with it. Some blood obtained from the 
spleen of a bullock that died of splenic fever at Rigsby, on 
March Gth, was introduced into the subcutaneous cellular tissue 
of a guinea-pig on the evening of March 8th, and only a slight 
local effect was produced ; that the bullock from which the blood 
was taken died of splenic fever was proved by the presence of 
bacilli in the blood when examined on the 7th, and the spleen 
was much enlarged, weighing 14J lbs. On April 8th blood 
from a heifer that died of splenic fever on the Gth was used to 
inoculate a guinea-pig, and produced no result. Similar failures 
occurred with blood from guinea-pigs that had died of anthrax 
when decomposition had set in before the material was collected. 
The fresh anthrax blood, when spread on a thin layer in a 
watch-glass and dried quickly at a temperature not exceeding 
40° C, retained its activity for weeks ; and some of the blood 
obtained from Rigsby on February 18th, thus treated, was suc- 
cessfully used for inoculations in May. The dried blood from 
some of the guinea-pigs was also used successfully after having 
been kept in a dry state for several days. 
II. Inoculation of Cattle. 
At the time of the first outbreak of splenic fever on Mr.^Mason's 
farm, there were no small bovine animals at the Brown Institution 
* Bacillus anthracis is the name given to the living microscopical organism 
•which is always found in the blood and diseased parts of animals affected with 
anthrax. 
