Inoculation 89 



(6) Experimental Infection. i. Inoculation: The oldest 

 experiments in immunity date from unknown antiquity and 

 were practised in China and other Oriental countries for the 

 purpose of preventing smallpox. The Chinese method of ex- 

 perimentally producing variolous infection was very crude 

 and consisted in the introduction of the crusts from cases of 

 variola into the nose, and tying them upon the skin. The 

 Turkish method was much more neat, in that a small quan- 

 tity of the variolous pus was introduced into a scarification 

 upon the skin of the individual to be protected. Lady Mon- 

 tague, wife of the British Ambassador, brought the so-called 

 "inoculation" method of preventing smallpox from Turkey 

 in the early part of the eighteenth century (1718). By both 

 methods the very disease, variola, against which protection 

 was desired, was occasioned, the only advantage of the ex- 

 perimental over the accidental infection being that by select- 

 ing the infective virus from a mild case of variola, by per- 

 forming the operation at a time when no epidemic of the 

 disease was raging, and by doing it at a time when the person 

 infected was in the most perfect physical condition, the dan- 

 gers of the malady might be mitigated. 



The danger always existed, however, that the induced 

 disease being true variola might prove unexpectedly severe, 

 and that each inoculated individual, suffering from the con- 

 tagious disease, might start an epidemic. 



2. Vaccination: In 1791 a country schoolmaster named 

 Plett, living in the town of Starkendorf near Kiel in Germany, 

 seems to have made the first endeavor to subject to experi- 

 mental demonstration the oft-repeated observation that 

 persons who had acquired cow-pox did not subsequently be- 

 come infected with smallpox, by inserting cow-pox virus into 

 three children, all of whom escaped smallpox. 



The father of vaccination, and the man to whom the world 

 owes one of its greatest debts, was Edward Jenner, who 

 performed his first experiment on May 14, 1796, when he 

 transferred some of the contents of a cow-pox pustule on 

 the arm of a milkmaid named Sarah Nelmess to the arm of 

 a boy named John Phips. After the lad had recovered from 

 the experimental cow-pox thus produced, he subsequently 

 introduced smallpox pus into his arm and found him fully 

 immunized and rendered insusceptible to the disease. This 

 led Jenner to perform many other experiments, and record 

 his observations in numerous scientific memoirs. The 



