﻿MODERN THEORIES IN RELATION TO IMMUNITY. 81 



we are accustomed to associate with what we term immunity,, but surely 

 the line can not be an abrupt one and hence, in this investigation we 

 must seek chemical individuals of known constitution which, under 

 proper conditions, are capable as synthetic bodies of entering into 

 metabolic reactions. The recent work of Emil Fischer on the amino-acicls 

 and the synthetic formation of the polypeptide is suggestive and it is 

 with similar synthetic substances that we may hope to see our next great 

 advance in the study of immunity. 



The problems to be encountered in immunization are difficult, they 

 involve painstaking experimental work and close reasoning and thought 

 but, as I have endeavored to show, the modern views of chemistry and 

 physics are all on the side of the worker in immunity; he has but to 

 reason closely to untangle one more skein of the web, and his reward 

 is great. In place of the constant fear of recurring serious epidemics 

 of devastating diseases with their accompanying vast expenses, and in 

 place of the constant vigilance necessary to prevent serious outbreaks of 

 infections diseases, the worker in immunity may possibly as a result of his 

 studies in the future be able to render a community practically safe from 

 all but negligible sporadic cases. We could then dispense with the rigors 

 of quarantine and its interruption of commerce, or with the enormous loss 

 of life consequent upon the occurrence of epidemics. True, the prejudice 

 against methods of immunization is as yet great, much more of a 

 scientific nature needs to be done, much of a missionary character under- 

 taken, but then not many years ago the very fact of the causation of 

 disease by microorganisms was the subject of the bitterest dispute and 

 many members of the medical profession itself were sceptical as to the 

 results which were to follow. However, the opposition of the profession 

 has practically disappeared, that of the laity will of necessity follow, and 

 our successors will find the way for future advance cleared for them 

 by the pioneers of to-day. 



