On the Vaccine Inccul-etion. 307 



immediately from Doctors Petchier and Odier, or from the 

 Bibliothequc Britannique. I have had lately two opportunities 

 to make experiments upon perfons who have undoubtedly had 

 the fmall-pox in their infancy. They are both medical men, 

 and confecjuently their teftimony is more admiffiblc than that 

 of moft others. Upon the one, the vaccine matter produced 

 no effect whatever; and upon the other, a very fmall fuper- 

 ficial veficle appeared, which changed foon into a cruft. In 

 one word, there was not the lead appearance of the true and 

 ufual cow-pock puftuie. They confirm your principle, that 

 one cannot have the cow-pock after the fmall-pox. One 

 iingle circumftance vexes me in my vaccine practice : it is 

 the frequency of inoculations that fail ; that is to fay, where 

 no puftuie nor inflammation is produced. I can fcarcely at- 

 tribute it to my method, which is the common puncture of 

 moft practitioners. I make it as fuperficial as I can, to avoid, 

 as much as poffible, to draw blood, which I believe can wafli 

 off the matter. I make one puncture on each arm. I fee 

 that in England, as well as abroad, inoculators are divided 

 upon the advantages of the puncture or of the incifion. You 

 and Dr. Jenner feem to make ufe of the puncture : Dr. 

 Woodville recommends ftrongly the incifion. At Geneva 

 they prefer the incifion; and here the puncture. I propofe. 

 now to make comparative trials; and to inoculate my firft. 

 twenty patients in one arm with the puncture, and in the- 

 other with the incifion. The difficulty of making the moft 

 fuperficial incifion without drawing blood, has hitherto in- 

 duced me to recommend the puncture. Upon the whole, I' 

 diflike much to be fo often under the neceffity of repeating 

 the inoculation. You will oblige me very much by favour-' 

 in<j; me with fome particulars upon this point. 



My fecond patient, where the two difeafes have gone on 

 together, has had alfo a very favourable fmall-pox. Two 

 fimilar cafes in England authorife you to believe that the 

 cow-pock can render the fmall-pox milder when they attack 

 the fame fubject together. 



The medical world is waiting with impatience for tl\e 

 work von have prornifed in your Statement; and I join my* 

 reiiuelt to Lhofe that muft already have becu addreilcd to you 



upoft 



