em to him a point worth considering. He
knew that only his scientific brethren could gauge the advance in
knowledge, and consequent power over disease, due to his patient toil;
it was a question of minute discoveries, of investigations
unintelligible to the layman. Some of his colleagues held that he
foolishly restricted himself in declining to experimentalise _in
corpore vili_, whenever such experiments were attended with pain; he
was spoken of in some quarters as a "sentimentalist," a man who might
go far but for his "fads." One great pathologist held that the whole
idea of pursuing science for mitigation of human ills was nothing but a
sentimentality and a fad. A debate between this personage and Dr.
Derwent was brought to a close by the latter's inextinguishable mirth.
He was, indeed, a man who laughed heartily, and laughter often served
him where another would have waxed choleric.

"Only a dog!" he exclaimed once to Irene, apropos of this subject, and
being in his graver mood. "Why, what assurance have I that any given
man is of more importance to the world than any given dog? How can I
know what is important and what is not, when it comes to the ultimate
mystery of life? Create me a dog--just a poor little mongrel puppy--and
you shall torture him; then, and not till then. And in that event I
reserve my opinion of the----" He checked himself on the point of a
remark which seemed of too wide bearing for the girl's ears. But Irene
supplied the hiatus for herself, as she was beginning to do pretty
often when listening to her father.

Dr. Derwent was, in a sense, a self-made man; in youth he had gone
through a hard struggle, and but for his academic successes he could
not have completed the course of medical training. Twenty years of very
successful practice had made him independent, and a mechanical
invention--which he had patented--an ingenuity of which he thought
nothing till some friend insisted on its value--raised his independence
to moderate wealth. For his children's sake he was glad of this
comfort; like every educated man who has known poverty at the outset of
life, he feared it more than he cared to say.

His wife had brought him nothing--save her beauty and her noble heart.
She wedded him when it was still doubtful whether he would hold his own
in the fierce fight for a living; she died before the days of his
victory. Now and then, a friend who heard him speak of his wife's
family smiled with the thought