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erts the same action when inoculated upon children as the common 
vaccine, only that the development of the inoculatory pustules is 
more intensive in the first generations. Thiele was able to pass 
his new inoculative material through seventy-five human genera¬ 
tions, and to transmit the same to more than three thousand per¬ 
sons. The protective power of this variola vaccine was confirmed 
by testing inoculations with the true contagium of variola in twenty- 
one cases. Ceely obtained like results with variola vaccine, he 
and other English doctors proving it through more than sixty 
generations, by which it still retained its general characteristics ; 
the protective power of the same was tested by numerous inocu¬ 
lations with variola-pus. Variola vaccine, therefore, corresponds 
with the genuine cow lymph ; inoculation with it protects man 
from attacks of human variola. 
Badcock received positive results from inoculating a cow on 
the udder with variola; from eight cows vaccinated with variola 
he received positive results by three, and from the latter he made 
numerous inoculations, and proved this vaccine also to be a pro- 
phylacticum against human variola. Six further inoculations of 
cows with variola lymph proved negative, from which we see with 
what difficulty the contagium of human variola infects cattle, and 
vice versa. Senfft lias lately received positive results from his 
experimental inoculations of calves with variola-pus; he received 
local vaccine pustules without any indications of general disturb¬ 
ance or general exanthema. The further inoculations of a calf 
gave positive results; the animals were found non-susceptible to 
further vaccination. 
From these experiments we see that it is possible to develop 
variola vaccina from variola humana vera , and that our above 
mentioned conclusion, that the bovine variola descends from the 
true variola of man, is based upon facts. The bovine organismus 
lias the ability at the same time to reduce the contagious element 
of variola humana, and to transform the same to a benevolent 
vaccine contagium. This faculty is exactly opposed to that of 
sheep, by which we have seen that under certain circumstances, 
the contagium of vaccine became generalized, and assumed a ma¬ 
lignant form. In this case it appears as if the variola vaccine in 
