288 
GEORGE FLEMING. 
With regard to the pretended innocuousness of Thiele and 
Ceely’s so-called vaccination, reported to be as absolutely harm¬ 
less as true vaccination, the Commissioners did not believe that it 
was due to the passage of variolic virus through the bovine spe¬ 
cies, as it was found that it underwent a considerable attenuation 
in the organism of the ox, and could only be propagated through 
a very limited number of generations; but when returned to the 
human species, it appeared to regain all its activity. When first 
transmitted from man to the ox or horse it caused a very abun¬ 
dant, almost serious, secondary eruption, while all the children 
inoculated from this transferred virus had a discrete and almost 
insignificant eruption. The Commissioners clung to the opinion 
that Thiele and Ceely only practised variolisation, instead of vac¬ 
cination ; and they therefore gave the children they inoculated 
better prolection than if they had been vaccinated, if they did 
not expose them to more dangers. A question of much interest 
is that of the innocuousness of mediate variolation, and if it be 
proved to exist, the Commissioners thought recourse would at 
once be had to Thiele and Ceely’s method when good vaccine 
lymph could not be procured. But there is the grave danger of 
contagion; for in passing through the organism of animals the 
small pox virus loses none of its infectious properties. Experi¬ 
ence has only too well proved this, and this is why mediate vario¬ 
lation, like direct variolic inoculation, would create, if it became 
generalized, permanent centres of infection, which would soon 
cover nearly the whole globe. This danger does not exist with 
the vaccine virus; and therefore it is, that vaccination will always 
hold the first place in the prophylaxy of small-pox. 
I think I have now offered sufficient evidence of a clinical and 
experimental kind to prove that the variola of man is not that of 
the cow, and that by no possible means can the virus of the one 
be transmitted into that of the other. The bovine organism can¬ 
not reduce a general eruptive disease, due to an exceedingly infec¬ 
tious virus, to a merely contagious and very mild disorder, 
accompanied by a limited local eruption. iSTo more can the 
organism of the sheep ; for the many experiments which have 
been performed with the small-pox virus have not modified it in 
