INOCULATION OF SMALLPOX 347 



microbes, and we are now able to see that it is in adopting 

 her methods that our best hope of increasing that protec- 

 tion lies. Nature is satisfied if the efficacy of her defence 

 is sufficient to save enough individuals to carry on the 

 race. Man desires in the case of his own fellows to out-do 

 Nature, and to save all. 



A century and a half ago, before the true character of 

 infective disease was understood, it was observed that an 

 individual who was attacked by the smallpox and recovered 

 became incapable of receiving the infection again. He was 

 " protected " or "immune." The practice of " inoculation " 

 was introduced from the East by Lady Montague. The 

 infectious matter was introduced from a smallpox patient 

 into the person to be protected by rubbing it into a scarified 

 part of the skin. A much less severe attack of smallpox 

 was thus produced than that which usually followed the 

 natural infection, which (though we do not know precisely 

 its mode of entrance) is more widely spread through the 

 blood. At the same time the condition of " immunity " 

 after the attack was brought about with equal efficacy. 

 When Jenner introduced inoculation with " cowpox " for 

 the purpose of establishing " immunity " in the vaccinated 

 person, inoculation with smallpox itself was a very usual 

 practice. It was open to the objection that sometimes an 

 unexpectedly violent attack of the disease was produced, 

 resulting in death, and that the active infection was kept 

 alive and ever present in the community. The notion 

 with regard to the mode in which " immunity " was pro- 

 duced by either the Montacutian or Jennerian inoculation 

 was, even after the general knowledge of microbes as the 

 living contagion of disease had been arrived at, that the 

 mild attack due to inoculation " used up " something in 

 the blood — in fact, exhausted the soil, so that the infective 

 matter or microbe could no longer flourish in the blood. 

 And this view was accepted as the explanation of the 



