of neurasthenia. At Plymouth, while waiting for the ship to
sail, he complained of palpitation and pain about the heart, probably
due to a transient hyperthyroidism, brought on by excitement. During
the voyage, which lasted five years, he was afflicted often by
sea-sickness. A ship-mate relates that after spending an hour with the
microscope he would say "Old Fellow, I must take the horizontal for
it" and lie down. He would stretch out on one side of the table, then
resume his labors for a while when he again had to lie down. Already
fatigability had to be fed with rest. A serious illness that Darwin
claimed affected every secretion of his body acted probably as the
exhausting drain upon his adrenal potential.

The return to England was the date of onset for a record of continuous
illness, aggravated by his marriage, apparently, for his misery
increased progressively after it. So much so that he was forced to
leave London altogether so as to avoid the strain of social life, even
that of meeting his scientific friends or attending scientific society
meetings fatiguing him to exhaustion. After such occasions there would
be attacks of violent shivering, with vomiting and giddiness. It was
necessary for him to impose upon himself an absolute regime of daily
routine. Any interference with it upset him completely, and made it
impossible for him to do any work. Early morning was the only time for
physical as we; as mental exertion. Evening found him thoroughly used
up, with every move an effort. Insomnia made him its prey. A curious
sensitiveness to heat and cold distressed him. In 1859, when the
"Origin of Species" appeared, he wrote to a friend that his health had
quite failed, and that indigestion, headaches, with a looming hopeless
breakdown of body and mind made his life a burden and a curse. The
twenty years of research he devoted to the problems of evolution were
one long torture. For sixteen more years, during which he worked upon
and produced immortal classics of biology, he was the most wretched
and unhappy sufferer from neurasthenia. His life was a continuous
alternation of small doses of work and large doses of rest. So he
was enabled to publish twenty-three volumes of original writing and
fifty-one scientific papers. Living a sort of quasi-sanitarium life,
with the rules and regulations of one undergoing a rest cure for
thirty-six years, he thus accomplished infinitely more than the
millions who have led the stre