KEPORT OF THE ROYAL VACCINATION COMMISSION. 681 



Simpson (1892), and Hime (1892) ; but there are several others. The 

 ■details of the experiment are very scanty in the cases of Thiele and 

 Badcock, but more full in the others, especially, perhaps, those of Ceely 

 and Haccius. 



In the second category may be placed the experiments of Klein and 

 Copeman. Klein, who had in 1879 obtained in 31 trials what then 

 appeared simply negative results, found in a renewed research in 1892 

 that the result of the first inoculation in the cow of small-pox matter 

 was not a- distinct vesicle but merely a thickening and redness of the 

 wound. Lymph pressed from the thickened wound produced, when 

 inoculated into a second cow, a like result, but rather more marked ; 

 the thickening and reddening still further increased with a third and 

 a fourth cow. Lymph squeezed from the wounds of the fourth cow 

 produced in a child typical vaccine, and crusts from the child produced 

 typical vaccine in a cow. Copeman obtained somewhat similar results ; 

 "the appearances increasing in three removes and approaching ' those of 

 typical vaccine, but not reaching them. 



The third category consists of -the results obtained in an elaborate 

 inquiry conducted by a Commission of the Society of Medical Sciences at 

 Lyons, with Chauveau at its head. Those results, reported in 1865, were 

 briefly as follows : — 



Inoculation of the cow with small-pox matter in any one of the 30 

 animals used did not give rise to a vaccine vesicle. Nevertheless a 

 definite result was obtained ; in the form, however, not of a vesicle, but 

 -of a thickening and inflammation of the wound ; when a puncture was 

 employed this became a papule. Lymph squeezed from such a papule 

 and inserted into a second animal gave rise to a like papule ; and this, 

 again, might be used for a third animal, but often failed ; and the effect 

 could in no case be carried on through more than three or four removes. 



When the inoculation was repeated on an animal in which a previous 

 inoculation had produced such a papule, no distinct papule was formed ; 

 and, moreover, lymph squeezed from the seat of inoculation produced no 

 effect at all when used for the subsequent inoculation of another animal. 

 This shows that the development of the papule was the result of the 

 specific action of the virus. The same is shown by the fact that no such 

 papule was produced when the small-pox matter was inserted into an 

 aiximal which had previously had cow-pox naturally or artificially, as well 

 as by the fact that when an attempt was made to vaccinate, with vaccine 

 matter of proved efficacy, an animal on which a papule had been so 

 developed by inoculation with smaU-pox, the vaccination failed, though 

 the animal had never had natural cow-pox or had never been vaccinated. 

 The specific nature of the lymph of the papule is further shown by the 

 iact that such lymph when used' on the human subject gave rise to veri- 

 table small-pox. It has been urged that in this case the virus producing 

 -the effect was simply the old virus used in the inoculation, producing 

 the papule and still cUnging to the wound. This is disproved by the 

 experience that lymph from a papule of the second remove also gave rise in 

 the human subject to veritable small-pox. 



Thus Chauveau andbis Commission found that small-pox implanted 



