decided to
change a plan which produced so little success. Instead of intellectual
work he would engage in physical exercise, which, by exhausting his
muscular functions, would procure him the sleep of the laboring class;
and as he could not roll a wheelbarrow nor chop wood, every evening
after dinner he walked seven or eight miles rapidly.

Physical work succeeded no better than intellectual; he endured the
fatigue of butchers and wood-choppers, but he did not obtain their
sleep. Decidedly, bodily fatigue was worth no more than that of the
brain. It was worth even less. At his table, plunged in his books, or
in his laboratory over his microscope, he absorbed himself in his work,
and, by the force of a will that had been long exercised and submissive
to obedience, he was able to keep his thoughts on the subject in hand,
without distraction as without dreams. Time passed. But when walking
in the streets of Paris, in the deserted roads on the outskirts, by the
Seine or Marne, his mind wandered where it would; it was the mistress,
and it always dwelt on Madame Dammauville, Caffie, and Florentin. It
seemed as if the heat of walking started his brain. When he returned in
this state, after many hours of cerebral excitability, how could he
find the tranquil and refreshing sleep, complete and profound, of the
laboring classes who work only with their muscles?

Never having been ill, he had never examined nor treated himself:
medicine was good for others but useless for him. With a machine
organized like his he need fear only accidents, and until now he had
been spared them; a true son of peasants, he victoriously resisted
Paris life as the destroyer of the intellect. But the time had come
to undertake an examination and to try a treatment that would give
him rest. He was not a sceptical doctor, and he believed that what he
ordered for others was good for himself.

The misfortune was that he could not find in himself any of the causes
which resolve into insomnia; he had neither meningitis nor brain fever,
nor anything that indicated a cerebral tumor; he was not anaemic; he ate
well; he did not suffer with neuralgia, nor with any acute or chronic
affection that generally accompanied the absence of sleep; he drank
neither tea nor alcohol; and without this state of over-excitement of
the encephalic centres, he might have said that he was in good health, a
little thin, but that was all.

It was this excitement that he must cure