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GEORGE FLEMING. 
in this way. The experiments were continued; altogether ten 
animals were variolised, and then vaccinated some days after¬ 
wards ; but six had no vaccinal eruption whatever, three had rudi¬ 
mentary and ephemeral pustules, and one only showed a regular 
and characteristic cow-pox. Considering the readiness, as was 
afterwards found, with which true cow-pox, human vaccinia, and 
horse pox could be inoculated, and that the former could only be 
produced very exceptionally when the animals had been previ¬ 
ously variolised, the conclusion arrived at by this important 
chance discovery was that variolisation exercises a neutralizing in¬ 
fluence on the development of vaccinia ; and that the slightly- 
marked eruption, so undecided in character, caused by the inocu¬ 
lation of small-pox virus on bovines, is of a specific nature—in 
this species presenting, with the cow-pox, the same relations that 
variola and vaccinia do to each other in the human species. 
It is curious to note that, in 1863, the same (Lyons) Commis¬ 
sion was desirous of discovering whether small-pox could be 
transmitted to animals, and they made a number of inoculations, 
but all these apparently failed. Subsequently the animals were 
inoculated with human vaccine, and the same negative result fol 
lowed. But it was never suspected then that the vaccination 
failures were due to the previous variolation, supposed to be inef¬ 
fective, and it was concluded either that human vaccine takes with 
difficulty on the bovine species, or the animals experimented upon 
had previously been affected with cow-pox. It would thus appear 
to be demonstrated in the clearest manner that variola and vacci¬ 
nia are related, or rather opposed, to each other in the bovine 
species, in the same way as they are in mankind. The negative 
results following variolation in animals which had been success¬ 
fully vaccinated, was a crucial test of the soundness of this dem¬ 
onstration. Three animals—a cow and two calves—were vario¬ 
lised and vaccinated at the same time, the small-pox matter being 
inoculated on the left side of the vulva, the vaccine lymph on the 
right. In the three there appeared on the right side the very 
characteristic vaccinal eruption, and on the left the typical papu¬ 
lar eruption engendered by variolation, as in two of Ceely’s ex¬ 
periments. 
