200 
F. S. BILLINGS. 
of the cows, and from the last, children were successfully inocu¬ 
lated through several generations. At the same time variola vac¬ 
cine did not prevail among the remaining cattle of the valley. 
That no complication was in this case made with the exanthema 
of aphthae epizooticse is proven by the fact that the cows were 
subsequently attacked by the latter disease. Other very interest¬ 
ing and thoroughly confirmed cases of positive infection are re¬ 
ported by Ceely in his very interesting work, “ Observation over 
Cow Pock,” (variola vaccina) and Vaccination, etc.” Dinter 
made similar observations in Saxony in 1860 ; and in the Prussian 
Veterinary Report, 1855-’65, the same phenomena are mentioned, 
viz: the coeval appearance of humana and bovine variola. In 
Holstein, epizootics of vaccina and variola epidemics have been re¬ 
peatedly observed. 
We observe, therefore, that human variola may be trans¬ 
formed into vaccina through both artificial and accidental trans¬ 
mission, and have in this way secured a safe indicator in our search 
for the origin of variola vaccina. V. vaccina generated in this 
manner distinguishes itself in no way from the so-called pure or 
original bovine variola, and deports itself in exactly the same 
manner as well with regard to further inoculations of cattle and 
man, as with regard to the activity of the inoculating lymph, and 
its protective power. As, however, variola vaccine comes to pass 
in all directions, although in a sporadic form, either by individu¬ 
als, or enzootic, limited to stables or herds, it must be evident 
that it is impossible, that it should in all cases owe its (direct) 
genesis to human variola. The latter coincides with v. vaccina 
only in exceptional cases, and generally fails far and near in re¬ 
gions and times when v. vaccina breaks out, a point Bohn espe¬ 
cially emphasises. 
We must yet seek for still other springs from which this 
bovine malady takes it origin, as we cannot on any account con¬ 
cede to it an abiogenetic origin. Although individual authors 
have asserted that the fact, that this bovine malady comes to pass 
in places where neither humana or equine variola were to be 
found, speaks strongly for its epigenetic origin, yet they entirely 
overlook the fact that vaccination is practiced on all sides. As 
