utoring students in anatomy. His sure hand and clear decision in
any situation marked him as a practitioner of power, and he had
thoughts once of devoting himself to the most delicate of all
surgery,--that of the eye. He was even then groping for his
life-work, without knowing it, for it was always light, light--the
source or avenue or effect of it--that held him. And presently his
work found him.

It has been said that Finsen was a sick man. A mysterious malady[1]
with dropsical symptoms clutched him from the earliest days with
ever tightening grip, and all his manhood's life he was a great but
silent sufferer. Perhaps it was that; perhaps it was the bleak North
in which his young years had been set that turned him to the light
as the source of life and healing. He said it himself: "It was
because I needed it so much, I longed for it so." Probably it was
both. Add to them his unique power of turning the things of everyday
life to account in his scientific research, and one begins to
understand at once his success and his speedy popularity. He dealt
with the humble things of life, and got to the heart of things on
that road. And the people comprehended; the wise men fell in behind
him--sometimes a long way behind.

[Footnote 1: The autopsy which he himself ordered on his death-bed
as his last contribution to medical knowledge, showed it to be a
slow ossification of the membrane of the heart, involving the liver
and all the vital organs. He was "tapped" for dropsy more than
twenty times.]

In the yard of Regentsen there grows a famous old linden tree.
Standing at his window one day and watching its young leaf sprout,
Finsen saw a cat sunning itself on the pavement. The shadow of the
house was just behind it and presently crept up on pussy who got up,
stretched herself, and moved into the sunlight. In a little while
the shadow overtook her there, and pussy moved once more. Finsen
watched the shadow rout her out again and again. It was clear that
the cat liked the sunlight.

A few days later he stood upon a bridge and saw a little squad of
insects sporting on the water. They drifted down happily with the
stream till they came within the shadow of the bridge, when they at
once began to work their way up a piece to get a fresh start for a
sunlight sail. Finsen knew just how they felt. His own room looked
north and was sunless; his work never prospered as it did when he
sat with a friend whose room was on the south side