506 THE LIFE-WORK OF A CHEMIST. 



refractory to toxic doses of the poisou, but also even to the microbe 

 itself. So that instead of introducing the micro-organism itself into 

 the body, it may now only be necessary to vaccinate with a chemical 

 substance which in large doses brings about the disease, but in small 

 ones confers immunity from it, reminding one of Hahnemann's dictum 

 of " Similia similibus curantur." 



Here then we are once more on chemical ground. True, on ground 

 which is full of unexplained wonders, which however depend on laws 

 we are at least in part acquainted with, so that we may in good heart 

 undertake their investigation, and look forward to the time when 

 knowledge will take the iilace of wonder. 



In conclusion, I feel that some sort of apology is needed in thus 

 bringing a rather serious piece of business before you on this occasion. 

 Still I hope for your forgiveness, as my motive has been to explain to 

 you as clearly as I could the life-work of a chemist who has in my 

 opinion conferred benefits as yet untold and perhaps unexampled on 

 mankind, and I may be allowed to close my discourse with the noble 

 words of our hero spoken at the opening of the Pasteur Institute in 

 the presence of the President of the French Republic : 



"Two adverse laws seem to me now in contest. One law of blood 

 and death, opening out each day new modes of destruction, forces 

 nations to be always ready for the battle-field. The other a law of 

 peace, of work, of safety, whose only study is to deliver man from the 

 calamities which beset him. 



"The one seeks only violent conquests. The other only the relief of 

 humanity. The one places a single life above all victories. The other 

 sacrifices the lives of hundreds of thousands to the ambition of a single 

 individual. The law of which we are the instruments, strives even 

 through the carnage to cur© the bloody wounds caused by this law of 

 war. Treatment by our antiseptic methods may preserve thousands 

 of soldiers. 



"Which of these two laws will prevail over the other? God only 

 knows. But of this we may be sure, that science in obeying this law 

 of humanity will always labor to enlarge the frontiers of life." 



