216 EDWARD JENNER 



mation, whether springing up spontaneously or arising 

 from the application of acrid substances, such for instance, 

 as cantharides, pix Burgundica, antimonium tartarizatum, 

 etc., will often produce cutaneous affections, not only near 

 the seat of the inflammation, but on some parts of the 

 skin far beyond its boundary, is a well-known fact. It is, 

 doubtless, on this principle that the inoculated cow-pock 

 pustule and its concomitant efflorescence may, in very ir- 

 ritable constitutions, produce this affection. The eruption 

 I allude to has commonly appeared some time in the third 

 week after inoculation. But this appearance is too trivial 

 to excite the least regard. 



The change which took place in the general appear- 

 ance during the progress of the vaccine inoculation at the 

 Smallpox Hospital should likewise be considered. 



Although at first it took on so much of the variolous 

 character as to produce pustules in three cases out of 

 five, yet in Dr. Woodville's last report, published in June, 

 he says: "Since the publication of my reports of inocu- 

 lations for the cow-pox, upwards of three hundred cases 

 have been under my care ; and out of this number only 

 thirty-nine had pustules that suppurated ; viz., out of the 

 first hundred, nineteen had pustules; out of the second, 

 thirteen ; and out of the last hundred and ten, only seven 

 had pustules. Thus it appears that the disease has be- 

 come considerably milder; which I am inclined to attribute 

 to a greater caution used in the choice of the matter, with 

 which the infection was communicated; for, lately, that 

 which has been employed for this purpose has been taken 

 only from those patients in whom the cow-pox proved 

 very mild and well characterized." 1 



The inference I am induced to draw from these premises 

 is very different. The decline, and, finally, the total ex- 

 tinction nearly, of these pustules, in my opinion, are more 

 fairly attributable to the cow-pox virus, assimilating the 

 variolous,* the former probably being the original, the lat- 



1 In a few weeks after the cow-pox inoculation was introduced" at the 

 Smallpox Hospital I was favoured with some virus from this stock. In the 

 first instance it produced a few pustules, which did not maturate; but in 

 the subsequent cases none appeared. E. J. 



In my first publication on this subject I expressed an opinion that the 

 smallpox and the cow-pox were the same diseases under different modifica- 







