HUMAN AND ANIMAL VARIOLAS. 
431 
pox inoculated on the cow produces what in every way corres¬ 
ponds to cow-pox, or on man to vaccinia. From the cow and 
man horse-pox can be transmitted indefinitely; and while its ac¬ 
tion is modified by repeated transmissions, its protective influence 
against variola is undiminished. This has been demonstrated 
times almost without number, from the days of Jenner up to the 
present date. The most interesting and instructive of recent 
demonstrations in this direction is that recorded by Dr. Pingaud, 
in a communication presented to the Paris Academy of Medicine 
a few months ago. Having observed, with Drs. Yiseux and 
Thomas, an epizooty of horse-pox in February, 1879, he deter¬ 
mined to make some experiments, and selected as a vacciniferous 
subject a four-years-old horse affected with the disease, but whose 
antecedents w'ere well known, and whose health at other times 
was excellent. The cutaneous eruption was discrete ; there were 
only a few crusts of pustules about the hollow of the pasterns; 
but in the mouth, and within the upper lip, the mucous membrane 
was studded with vesicles offering the characteristic nacrous as¬ 
pect. Lymph was collected from these pustules with the greatest 
care, and seven young soldiers of the 10th Hussars, who had not 
been vaccinated, were inoculated. On the sixth day, six of the 
men showed at the seat of inoculation the characteristic vaccine 
vesicles, which had a somewhat inflamed base. From four of the 
soldiers lymph was caken; with this sixty-four men—eight of 
whom had not been vaccinated—were inoculated. In forty of 
these the result was positive—sixty per cent, successful vaccina¬ 
tions. With none of the patients were there any serious inflam 
matory symptoms, and only in a very small number did the inoc¬ 
ulations assume a furunculous aspect. Calves were inoculated 
from the horse, but the proportion of successes were only 48 per 
cent., rather going to prove that the virus became weakened in 
the calves. 
On May 5th, 1880, a case of horse-pox was discovered in Paris 
among the horses of a German horse dealer. A three-months-old 
heifer was inoculated on May 5th, with matter from this horse, 
the inoculations being made by three punctures on the udder. 
The result was a complete success; and from this animal another 
