426 A SHORT HISTORY OF SCIENCE 



Small Pox, one of whom had it very full, he remained in the house 

 with them, but received no injury from exposure to the contagion. 



It is necessary to observe, that the utmost care was taken to as- 

 certain, with the most scrupulous precision, that no one whose case 

 is here adduced had gone through the Small Pox previous to these 

 attempts to produce that disease. . . . 



CASE XVII 



The more accurately to observe the progress of the infection, I 

 selected a healthy boy, about eight years old, for the purpose of inocu- 

 lation for the Cow Pox. The matter was taken from a sore on the 

 hand of a dairymaid (Sarah Nelmes), who was infected by her master's 

 cows, and it was inserted, on the 14th of May, 1796, into the arm of 

 the boy by means of two superficial incisions, barely penetrating the 

 cutis, each about half an inch long. 



On the seventh day he complained of uneasiness in the axilla, and 

 on the ninth he became a little chilly, lost his appetite, and had a 

 slight head-ache. During the whole of this day he was perceptibly 

 indisposed, and spent the night with some degree of restlessness, but 

 on the day following he was perfectly well. 



The appearance of the incisions in their progress to a state of 

 maturation were much the same as when produced in a similar man- 

 ner by variolous matter. The only difference which I perceived was, 

 in the state of the limpid fluid arising from the action of the virus, 

 which assumed rather a darker hue, and in that of the efflorescence 

 spreading round the incisions, which had more of an erysipelatous 

 look than we commonly perceive when variolous matter has been 

 made use of in the same manner ; but the whole died away (leaving 

 on the inoculated parts scabs and subsequent eschars) without giving 

 me or my patient the least trouble. 



In order to ascertain whether the boy, after feeling so slight an 

 affection of the system from the Cow Pox virus, was secure from the 

 contagion of the Small Pox, he was inoculated the 1st of July follow- 

 ing with variolous matter, immediately taken from a pustule. Several 

 slight punctures and incisions were made on both his arms, and the 

 matter was carefully inserted, but no disease followed. The same 

 appearances were observable on the arms as we commonly see when 

 a patient has had variolous matter applied after having either the Cow 



