CLASS II. i. 3. 9. OF SENSATION. 207 



f mall-pox : to all whom in that fituation it is dangerous, as it 

 generally produces mifcarriage, and frequently death. Dr. 

 Cappe, in an ingenious paper in the York Herald, obferves, that 

 the vaccine difeafe is never communicated but by contact, and 

 then only when the matter lies on the broken ikin - 9 and that 

 many women during pregnancy have paffed through this dif- 

 eafe, and none have fuffered from it ; and that inftead of behi 

 peculiarly dangerous to young infants, as the fmall-pox is, it 

 feems to be peculiarly mild to them. 



From all thefe circumftances it may be hoped, that the inoc- 

 ulation of the cow-pox may become fo general, and performed 

 fo early in life, as totally to eradicate the fmall-pox ; by which 

 latter difeafe above two thoufand perfons are (hewn by Dr. 

 Cappe, by the bills of mortality, to be annually deftroyed in a 

 part of London only. 



As the cow-pox is fo much lefs infectious than the fmall-pox, 

 it requires much more care in the inoculation to give the difeafe 

 with certainty ; whence it fometimes has happened, that a flight 

 inflammation from the puncture of the lancet has been miftaken 

 by the unfkilful for the vaccine difeafe : and I have heard of four 

 fuch patients in this country who have afterward taken the 

 fmail-pox. But as Dr. Woodville inoculated a thoufond people 

 with the fmall-pox, who had previoufly received the cow-pox, 

 without one of them taking the infection, there can be no doubt 

 but that the four patients above mentioned had not previoufly 

 undergone the vaccine difeafe ; and ought not therefore to dif- 

 credit this fortunate and wonderful difcovery. 



In the counties where the cows are fubject to this difeafe, the 

 milking is performed principally by men-fervants ; and it is 

 there believed, as Dr. Jenner mentions, that the difeafe was pre- 

 vioufly given to the paps of the cows by the hands of the men 

 who milked them, and who had previoufly acquired the infec- 

 tious matter from the heels of horfes, which difcharged an acrid 

 fames, when they had a difeafe called the greafe. This may be 

 worth further investigation ; as the prefervation of people from 

 the fmall-pox, by their having undergone the cow-pox, is fo won. 

 derful a phenomenon, fo contrary to our previous knowledge of 

 any analogy between the infectious difeafes of men and quadru- 

 peds, that other facts equally furprifing may exift. May not the 

 fmall-pox have been originally acquired from the cow-pox ? 

 which latter, having been a much older difeafe, may by procefs 

 of time have become milder than the former : as the fmall-pox 

 is believed alfo to have become much milder than formerly ; ow- 

 ing probably to the incapacity of receiving it, which exifls in 

 thofe who have undergone that diicaie, having in procefs of time 



become 



