THE PRODUCTION OF IMMUNITY. 
521 
a practical continuation of the experiments of Drs. Salmon 
and Smith made upon pigeons in 1877, in which sterilized 
culture-media were used for preventive inoculation. We re¬ 
fer further to the bulletin of the Bureau on “ Hog Cholera,” 
published in 1889, in which are recorded a number of experi¬ 
ments upon hogs, sterilized culture-media being used for the 
purpose of producing immunity. 
This work of Drs. Salmon and Smith was the pioneer work 
in preventive inoculation with other than some form of the 
germ of the disease itself, and the work now recorded was, 
of course, under the advice and direction of Dr. Salmon as 
head of the Bureau of Animal Industry. Without the careful 
bacteriological study of hog cholera which has been made by 
the Bureau of Animal Industry, our work would have been 
impossible. For our laboratory experiments guinea-pigs were 
used, as being convenient to handle and susceptible to hog 
cholera. They have proved very satisfactory. The material 
used for inoculation was prepared in the chemical laboratory 
by modifications of methods already described, and by other 
methods which will be explained in more detail at some fu¬ 
ture date. The testing of the materials used, to determine 
that they "were free from germs, and the greater part of the 
preventive inoculations, were made by Dr. Moore, with such 
quantities of substance and at such times as we thought best. 
The autopsies were also made by Dr. Moore, and the work 
thereby greatly facilitated. 
As to the name which should be given to the ptomaines 
and albumins from the hog cholera culture-liquids, until their 
chemical constitution is more thoroughly studied, it would 
seem best, as there are several distinct swine diseases, to call 
the ptomaines from the hog cholera germs, as a class, Sucho- 
lotoxins, and the ptomaine, which appears to be the principal 
factor, Sucholotoxin ( Su —a hog, cholo —cholera, and toxus — 
poison). Sucholo-albumin would seem to be sufficiently dis¬ 
tinctive for the albumin of these culture-liquids. As Hankin* 
shows, the name toxalbumin is hardly the correct one to ap- 
* British Medical Journal , 1889, p. 810. 
