16th May 1915. To-day I have at last accomplished my seventy years! I have attained the normal limit of life, a limit mentioned by King David and confirmed by the statistical researches of Lexis and Bodio.[32] I am still capable of work and of reflection. But the changes in my psychical state which I had observed a year ago have become sensibly accentuated. The difference in acuteness both of pleasant and painful sensations is becoming more and more marked. Agreeable sensations are becoming weaker; I am now indifferent to many things which I used to appreciate very much.
It is useless to say that I am indifferent to the quality of my food; my need of musical impressions has become so much less that I hardly feel the desire to satisfy it. The charm of spring no longer touches me and only provokes sadness in my mind.
On the other hand, my anxiety for the health and happiness of those I love is getting more and more acute. I find it difficult to understand how I ever could bear it.
The powerlessness of medicine grieves me more and more, and, as a last straw, the war has interrupted all the work that had been undertaken against disease. In these conditions, it is not astonishing that I should feel a growing satiety with existence. Last year [16th May 1914 to 16th May 1915] I had two attacks of tachycardia, during which I should have been glad to die, but in general my health is satisfactory and that sustains me. What would have become of me if, to crown my misfortunes, I had fallen ill! I certainly no longer fear death, but I desire to die suddenly during a heart attack and not to go through a long illness.
My comparative longevity is not due to family heredity (my father died in his 68th year, my mother in her 66th, my sister also, my eldest brother at 45, my second brother at 50, the third in his 57th year; my grandparents I have not known). It is to my hygiene that I give the credit for having attained my 70 years in a satisfactory condition. I have taken no raw food for eighteen years and I introduce as many lactic bacilli as possible into my intestines. But it is but a first step; in spite of all, I am being poisoned by the bacteria of butyric fermentation. However, I have practically reached the normal term of life and I must be satisfied. I have, so to speak, accomplished the programme of a “reduced orthobiosis.”
When macrobiotics become more perfect, when people have learnt how to cultivate a suitable flora in the intestines of children as soon as they are weaned from their mother’s breast, the normal limit of life will be put much further back and may extend to twice my 70 years. Then, also, satiety with existence will appear much later than it has done in my case.
To-day they celebrated my jubilee at the Pasteur Institute, which touched me very much, in spite of my distrust of sentimental manifestations, for I realised their sincerity. I should have liked to set out a programme of the researches which should be accomplished by the Pasteur Institute, but I feared to detain my audience too long.
I believe that Science will solve all the principal problems of Life and Death and that she will enable human beings to accomplish their vital cycle by real orthobiosis, not by a reduced caricature of it as in my case. Nevertheless, I consider the experiment practised upon myself as having already given some result and that is to me a real satisfaction.
We spent that summer a few weeks at Norka, where Metchnikoff completed his researches concerning the death of the silk-worm moth.