"Why, they must be worth a large sum," muttered the doctor, pouring out some of the stones into his hand, but pouring them back with a shudder.

"How horrible!"

He did not say what was horrible, but hastily retied the bag and placed it back in the sleeping man's breast, before hurrying out into the surgery, and pacing to and fro in an agitated way.

CHAPTER NINE.

THE STRANGE ACCIDENT.

A change seemed to have come over Doctor Chartley. A short time before he was calm and placid, his movements were slow, and a pleasant stereotyped professional smile made his handsome face beam. But now all was changed; the smile had gone, and, as he had passed to and fro, the light from the gas bracket displayed a countenance puckered with curious lines and frowns, while the variations of shadow caused by his constantly-changing position seemed to have altered him into another man.

He went back into the consulting-room, and looked at his patient, to find him breathing more easily and plunged into a deep sleep; and as he bent over him his hand stole toward the prostrate man's breast.

He snatched it away angrily, and returned to the surgery, to resume his hurried walk, muttering to himself, his thoughts finding utterance in sound, till he started and looked about him, as if in dread of being overheard.

Stealing back to the consulting-room, he went to the closet, and took out the bottle 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 took the glass into which he had previously poured the brandy, and poured in a little more, to which he added sugar, and half-filled the glass with hot water from the kettle.

"He will be sure to drink that," he said, as he replaced the glass within easy reach of the sofa; and then removing the stopper from the blue bottle he held, replaced it partly in the neck, rested it upon the edge of the steaming glass, and began to count the drops which fell.

One--two--three.

Each drop at an interval after the one which had preceded it, while with his left hand he steadied the tumbler.

As the third drop fell into the glass there was a strange noise outside--a dull scuffling of feet, mutterings of voices, and then a low imperious tapping on the panel of the door.

At the first sound the doctor turned his head sharply and gazed in the direction of the door, while the rest of his body seemed to have become fixed in a cataleptic state, save that his eyes dilated and his jaw dropped.

And meanwhile, slowly and steadily, drip--drip--drip--drip, the globules of fluid fell from the tip of the blue bottle into the steaming glass at last in quite a stream.

A strange dread had overcome the doctor. His patient's words about his diamonds had proved to be true; were the rest, then, true--that he had been pursued by men whose aim it was to plunder, perhaps murder him, and they had really traced him down here?

"Bah! am I turning childish?" said the doctor, starting up, and letting the stopper fall back into its place in the bottle, just as his patient moaned slightly, turned impatiently in his sleep, and the ulster glided to the floor.

The doctor stooped quickly, raised it, and threw it over his patient, and, as he bent over him, listened intently to the repetition of the tapping.

"It might be," he said softly. "Pish! absurd! The wanderings of a diseased mind."

Catching up the bottle from where he had placed it on the table, he walked quickly towards the door, paused, returned, and stooped as if to pick up the poker. Then smiled at his folly.

He passed softly out of the door, and closed it after him, to go to the shelves in the dark, where he made a clicking noise among the bottles, as he reached up; for there in the darkness the feeling once more assailed him that his patient might be right, while for the third time, more plainly heard now, there came a sharp tapping.

The doctor crossed to the gas bracket, turned it up, and as its light filled the surgery, he walked boldly to the lobby-door, opened it, and the dull red glare from the fanlight over the outer door shone upon his handsome placid face.

The next moment he had opened the outer door, and was gazing at a group of three men.

Mark Heath's announcement flashed through his brain once more, and then gave place to the ideas furnished by his visitors.

"Thought you were a-bed. Couldn't find the bell. This cursed fog, sir.

Our friend here knocked down by a cab, and we saw your red light as we were trying to get him to our hotel."

"Tut, tut, tut!" ejaculated the doctor. "Bring him in, gentlemen."

He glanced at his visitors. Saw that they were well-dressed men in ulsters and low-crowned hats, and that the speaker was a well-built fellow with a closely-cut beard; while another was a rather Mephistophelean-looking man, with cheeks closely shaven, and upper lip bearing a bristly moustache.

Between them they supported a slight, young-looking companion, who was moaning slightly, but evidently making an effort to be firm.

"Mind, Harry--Rogers," he said, in a high-pitched voice, "it's as if something red-hot was running through my chest! Ah-h-h!"

"Support him, gentlemen," said the doctor. "Mind he doesn't faint.

Here, quick! Here!"

He spoke in sharp, decided tones, as he directed and helped them to lay the injured man upon the settee, where he subsided with a querulous cry, grinding his teeth the while, and compressing his lips.

"Kindly shut both doors," said the doctor; and the man who had first spoken, and who looked very pale, obeyed.

"So cursedly unlucky!" he said excitedly. "I never saw such a fog.

They've no business to allow men to drive fast on a night like this."