On the Vaccine Inoculation. 31 1 



I have had an opportunity in the courfe of my experiments 

 |o be convinced that the vaccine inoculation can have no 

 effect on thofe who have had the fmall-pox. C. Beugn£, 

 already mentioned, believed that he had never had the fmall- 

 pox. I inoculated him three different times with the vaccine 

 matter, but always without any effect. Being ftruck with this 

 phenomenon, I afked him fomequeftions, when he acknow- 

 ledged, that at the age of four years he had flept with one of 

 his lifters who had been attacked with the confluent finally 

 pox highly malignant, that he had been very fiek for feveraf 

 days, but that his mother did not think him infected with 

 the fmall-pox becaufe he had no puftules, which are the 

 ufual fymptom. This was an excellent opportunity fop 

 trying a new fort of counter-experiment : I inoculated 

 C. Beugne with the fmall-pox, but they took no effe6t. 



The fon of C. Genou, of Samer, aged nine years, had been 

 inoculated for the vaccine with frefh matter and of a good 

 quality. Four days after I went to examine the child, and 

 was much furprifed to obferve that the vaccine had produced 

 nothing, though the child had been inoculated in three dif* 

 ferent places. This experiment had feldom failed, except 

 when the fubject had before had the fmall-pox. On exa- 

 mining the child, I found him with a languid look, a bad. 

 pulfe, and a great deal of fever. I fufpected, therefore, that 

 he had been already infected with the fmall-pox at the time 

 when I inoculated him for the vaccine. On inquiring, t 

 found that the child had come from a houfe where the na-^ 

 tural fmall-pox prevailed, in order to be inoculated. I fore- 

 faw that he was going to have the natural eruption, and in- 

 deed the difeafe appeared on him two days after. It was of 

 the mild kind, and the punctures made for the vaccine were 

 dry, and almoft effaced. 



My experience proved to me alfo, that in the cafe where 

 the fubjeel is already infected with the fmall-pox, the vac- 

 cine inoculation, which then remains without any apparent 

 effect, adds nothing to the malignity of the fmall-pox. I ant 

 convinced that, whichever of the two infections is anterior 

 in point of action and progrefs, prevents the action and pro- 

 S s 3, gr eitf 



