“Macbeth does murder sleep, the innocent sleep;
        Sleep, that knits up the ravell’d sleeve of care,
        The death of each day’s life, sore labor’s bath,
        Balm of hurt minds.”

He also had lost it, “the innocent sleep, sore labor’s bath, balm of hurt minds.”  He had never been a great sleeper; at least he had accustomed himself to the habit, hard at first, of passing only a few hours in bed.  But he employed these few hours well, sleeping as the weary sleep, hands clenched, without dreaming, waking, or moving; and the thought that occupied his mind in the evening was with him on waking in the morning, not having been put to flight by others, any more than by dreams.

After Caffie’s death this tranquil and refreshing sleep continued the same; but suddenly, after Madame Dammauville’s death, it became broken.

At first it did not bother him.  He did not sleep, so much the better!  He would work more.  But one can no more work all the time than one can live without eating.  Saniel knew better than any one that the life of every organ is composed of alternate periods of repose and activity, and he did not suppose that he would be able to work indefinitely without sleep.  He only hoped that after some days of twenty hours of work daily, overcome by fatigue, he would have, in spite of everything, four hours of solid sleep, that Shakespeare called “sore labor’s bath.”

He had not had these four hours, and the law that every state of prolonged excitement brings exhaustion that should be refreshed by a functional rest, was proved false in his case.  After a hard day’s work he would go to bed at one o’clock in the morning and would go to sleep immediately.  But very soon he awoke with a start, suffocating, covered with perspiration, in a state of extreme anxiety, his mind agitated by hallucinations of which he could not rid himself all at once.  If he did not wake suddenly, he dreamed frightful dreams, always of Madame Dammauville or Caffie.  Was it not curious that Caffie, who until then had been completely effaced from his memory, was resuscitated by Madame Dammauville in the night, ghost of the darkness that the daylight dissipated?

Believing that one of the causes of these dreams was the excitement of the brain, occasioned by excessive work at the hour when he should not exercise it, but on the contrary should allow it to rest, he 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.