which contained the result of his studies, and looked at
it with a sigh. Then he raised the retort and its stand from the shelf,
shook his head, and replaced it.

"And if I only had money," he thought, "I could carry out my experiments
at my ease, and succeed. This miserable poverty would be no more; my
children would be happy; and I should win a name which would become
immortal."

He shook his head, his brow grew darker, and a terrible temptation
attacked him.

"No one saw him come here. It is his fancy that he has been followed.
One life. What is one life in this vast world? One life. Why, my
discovery perfected would be the saving of the lives of thousands,
hundreds of thousands, of generations of human beings in this teeming
earth. Suppose he slept and waked no more? Ah!"

The doctor stood gazing down at the sleeping man.

"Such temptations come to all," he said softly; "and I have seen so many
die that the passing away of one--well, what is it but the deep long
sleep into which I could make him glide without pain?

"Ah, and afterwards? Poor lad! He came to me for sanctuary, and I had
betrayed my trust. How could I look in the face of my son again--in the
eye of my girl? Those clear eyes would read my secret, and I should be
as one accurst."

He bent down over the sleeping man again, and in spite of himself his
hand stole gently towards his heart, trembling.

"They are worth thousands," he said, "and they lie there as if of the
value of a few pence. He came to me for refuge. Well, he shall not
find that I have failed."

There was no tremor in his hand now as he re-arranged the cover over
Mark Heath's breast, to stand afterwards calmly watching his guest; and
then to go out into the surgery, turn down the gas, and slowly pace the
floor, thinking deeply.

Every inch of the surgery was so familiar that the darkness was the same
to him as the light, and the bitter coldness of the place seemed to
refresh him.

At the end of a few minutes he stood perfectly still, thinking; and then
going to one of the shelves, he ran his hand softly along the top row of
small bottles, took one, and turned down the gas.

As he entered the consulting-room again, he glanced at the label, nodded
his head in a satisfied manner, and after a glance at his patient he
seemed to make up his mind what to do.

"Perhaps I shall sleep," he thought, "and if I do he may wake. It will
be a simple way."

He smiled as he