OLD AGE.« 



By Elie Metciinikoff, 

 i-!ub(lircct<)r of the Pasteur Jn.stHiilc. 



■ In compliance with the request of Doctor Toulouse, editor of the 

 Revue Scientifique, 1 will try to give you an idea of the present 

 state of our knowledge concerning old age, and I shall begin hy 

 speaking of the difficulty of the task which I have to perform. The 

 problem of old age is one of the most complicated and difficult found 

 in the biological field. As it is far from being solved it will be 

 impossible for me to present to you a completed study with results 

 sufficiently precise to be practically applied. On the other hand, 

 the course of procedure wdiich we jiui-sue in studying this (luestion 

 has already been made ]niblic, and consequently contains nothing 

 especially new. 



The reason why, in spite of these disadvantages, I have accepted 

 the proposition of M. Toulouse is because I wish to inform the pub- 

 lic concerning the extent of our investigations upon old age and to 

 make known what an innnense field yet remains to be covered before 

 we can arrive at a satisfactory^ solution of the problem. 



In considering this question of old age we are beset on every side 

 with difficulties. At what period of our life does this ultimate 

 stadium begin ; at what time ought a man to say that, having entered 

 upon this stage of his existence he dare no longer conduct himself 

 as an al)le-bodied individual? You will doubtless recall that it was 

 but a few months ago that the students of the faculty of medicine 

 in Paris loudly and noisily i)rotested against the decision of the 

 Senate that had suspended the law prescribing a limit of age for the 

 professors. '' We do not want old dotards," declared these young 

 men. It is not rare to see old scientists of very great merit remain in 

 their chairs up to an age when they are no longer capable of assim- 

 ilating scientific progress, of judging correctly concerning new ad- 

 vances. Their auditors readily see that they are no longer abreast 



a A lecture given in tlie Salle des Agriculteurs, rue d'Atlienes, July 8, 1904. 

 TranslMtod. by permission, from tbe lievue Scientifique (I'aris), 5tli series, Vol. 



U. pp. C.l-TO and 97-105. 



533 



