vm CONQUEST OF DISEASE 207 



Jenner was in his teens and in the first stage of his 

 medical education at Sodbury, Gloucestershire, when 

 his attention was directed to the subject of protection 

 against smallpox. A young girl came there for advice, 

 and on smallpox being mentioned she exclaimed, " I 

 cannot take that disease, for I have had cow-pox." 

 She, like other milkmaids in Gloucestershire and else- 

 where, had discovered for themselves that cow-pox 

 was a safeguard against smallpox ; but it required the 

 insight and patient labour of Jenner to transform a 

 piece of folklore into a scientific truth, and make the 

 medical profession all over the world receive it as 

 such. 



When Jenner went to London, at the age of twenty- 

 one, and was entered as a student at St. George's Hos- 

 pital, he mentioned this belief to John Hunter, who gave 

 his pupil this excellent piece of advice : " Do not think, 

 but try ; be patient, be accurate." On returning to 

 his native town of Berkeley to settle down into country 

 practice as a physician, the belief of the young girl at 

 Sodbury, and Hunter's wise words, were ever constant 

 in his mind. To get at the truth of this opinion was his 

 great object ; but it was not until 1780 that he felt 

 sufficient confidence to communicate to a friend his 

 ideas on the subject of propagating the protective cow- 

 pox from one individual to another, and so ultimately 

 staying the plague of smallpox. 



" Gardiner," said Jenner, " I have entrusted a most important 

 matter to you, which I firmly believe will prove of essential 

 benefit to the human race. I know you, and should not wish 

 what I have stated to be brought into conversation, for should 

 anything untoward turn up in my experiments, I should be made, 

 particularly by my medical brethren, the subject of ridicule, for 

 I am the mark they all shoot at." 



