APPENDIX G: JENNER 425 



the pustules in that disease. No erysipelas attends them, nor do they 

 shew any phagedenic disposition as in the other case, but quickly 

 terminate in a scab without creating any apparent disorder in the 

 Cow. This complaint appears at various seasons of the year, but 

 most commonly in the spring, when the Cows are first taken from 

 their winter food and fed with grass. It is very apt to appear also 

 when they are suckling their young. But this disease is not considered 

 as similar in any respect to that of which I am treating, as it is in- 

 capable of producing any specific effects on the human constitution. 

 However, it is of the greatest consequence to point it out here, lest 

 the want of discrimination should occasion an idea of security from 

 the infection of the Small Pox, which might prove delusive. 



[Hereupon follow detailed descriptions of numerous cases illustrating Jenner's 

 ideas. Of these we quote only two : Case I, illustrating Jenner's observations of 

 immunity to smallpox acquired naturally by accidental inoculation or vaccination 

 with cowpox virus, and Case XVII, his first and therefore most famous example 

 of experimental inoculation (or vaccination) upon the person of a boy named James 

 Phipps. This, the earliest experiment of the kind ever made, occurred on May 14, 

 1796.} 



CASE I 



Joseph Merret, now an Under Gardener of the Earl of Berkeley, 

 lived as a servant with a Farmer near this place in the year 1770, 

 and occasionally assisted in milking his master's cows. Several 

 horses belonging to the farm began to have sore heels, which Merret 

 frequently attended. The cows soon became affected with the Cow 

 Pox, and soon after several sores appeared on his hands. Swellings 

 and stiffness in each axilla followed, and he was so much indisposed 

 for several days as to be incapable of pursuing his ordinary employ- 

 ment. Previously to the appearance of the distemper among the 

 cows there was no fresh cow brought into the farm, nor any servant 

 employed who was affected with the Cow Pox. 



In April, 1795, a general inoculation taking place here, Merret was 

 inoculated with his family ; so that a period of twenty-five years had 

 elapsed from his having the Cow Pox to this time. However, though 

 the variolous matter was repeatedly inserted into his arm, I found it 

 impracticable to infect him with it ; an efflorescence only, taking on 

 an erysipelatous look about the centre, appearing on the skin near 

 the punctured parts. During the whole time that his family had the 



