HAMILTON SCIENTIFIC ASSOCIATION. 47 



against a second attack of the same germ. The amboceptors- for 

 typhoid are special for that germ, and will not do for the destruc- 

 tion of an3^ other. The complement, on the other hand, seems to 

 work with any amboceptor. All authorities are not agreed on 

 this, however. 



In conclusion, these are the main facts and the most generally 

 accepted theories of immunity as it is understood to-day. What 

 may be taught fifty years, yea even five years, hence no man can 

 tell. This is an age of rapid advancement. Theories to-day are 

 history to-morrow. 



Yet it must not be understood that I have given you in any 

 sense a full account of the various phenomena that arise in connec- 

 tion with investigations on this subject. The fringe only has been 

 skirted. The less difficult parts of the route have been selected, 

 with due regard, however, to the main line of travel. I have pur- 

 posely avoided difiiculties, contradictions and theories which are 

 still largely in dispute. Knough has been said, however, to il- 

 lustrate how fearfully and wonderfully we are made, and how 

 little man yet knows and how much has yet to be learned regard- 

 ing the human body — the most wonderful of all the great works 

 of the Great Creator. Truly, "The greatest study of mankind 

 js man." 



J. e;dGAR DAVEY, M.B, 



