332 
ROBERT GRAHAM. 
The results indicate success in many herds, though the report 
was very incomplete at the time it was submitted. 
* Ulenheuth, of Germany, has published results in attenuating 
the virus. He states that it is practically impossible to find out 
the influence of different temperatures on the virus of swinepest: 
78° C.-70 0 C. killed virus in one hour; 58° C. for one hour 
killed the virus and in some cases it did not; 6o° C. for sixteen 
to twenty-four hours, it lost its virulence; twenty-four hours’ 
heating, 45-46° C., did not lose the power to produce disease. 
The following notes and experiments are an illustration of 
the inconsistency of this vaccine, with conclusions demonstrating 
that, with our results, it would be unsafe to use under ordinary 
farm conditions. Many of these experiments have, no doubt, 
been duplicated by every experiment station interested in serum 
production, at some other time. 
Our technique has been simple, yet what we considered suffi¬ 
cient for attenuating virus in the liquid blood if such were pos¬ 
sible. It was as follows, except when designated otherwise in 
certain experiments: 
Technique .—The virus was drawn from the carotid artery 
under aseptic precautions in advanced cases of hog cholera. The 
blood so drawn was defibrinated and placed in Erlemeyer sterile 
flasks loosely stoppered with sterile cotton. The flask was then 
placed in a luke-warm water bath and gradually brought up to 
a certain temperature (50-60° C.). Time was recorded from 
the instant it reached this temperature, and held at this degree 
for one hour, or one-half hour. The thermometer was placed 
about one and one-half inches from the surface in the water bath. 
The Erlemeyer flasks were then allowed to cool in room tem¬ 
perature from one to two hours, and then placed in the ice chest 
after carbolizing and sealing the container air tight. The virus 
so heated and cooled was used the same day, unless otherwise 
stated, in one-half to two centimetre doses, in intramuscular inoc¬ 
ulation in hogs weigfiing from 30 to 125 pounds. 
Lack of space prevents us from publishing a detailed account 
* Arbeiten a. d. Kaiserl. Gesundh. 
