In four years what will be my moral and intellectual condition?
How should I support this exile of four years?
Imagine the effect that four years of isolation in the mountains will produce.

But this is not all.

Besides this ostensible end that I have pursued since I left my village, I have my special work that I can carry out only in Paris.

Without having overwhelmed you with the details of medicine, you know that it is about to undergo a revolution that will transform it.

Until now it has been taught officially, in pathology, that the human organism carries within itself the germ of a great many infectious diseases which develop spontaneously in certain conditions; for instance, that tuberculosis is the result of fatigue, privations, and physiological miseries.