“This is my particular sanctum, Miss Durant; and as I have a reprehensible habit of night-work, I keep them as a kind of sleeping potion.”

Constance glanced about the room with more interest, and as she noticed the simplicity and the bareness, Swot’s remark concerning the doctor’s poverty came back to her.  Only many books and innumerable glass bottles, a microscope, and other still more mysterious instruments, seemed to save it from the tenement-house, if not, indeed, the prison, aspect.

“Are you wondering how it is possible for any one to live in such a way?” asked the doctor, as his eyes followed hers about the room.

“If you will have my thought,” answered Constance, “it was that I am in the cave of the modern hermit, who, instead of seeking solitude, because of the sins of mankind, seeks it that he may do them good.”

“We have each had a compliment to-night,” replied Dr. Armstrong, his face lighting up.

The look in his eyes brought something into the girl’s thoughts, and with a slight effort she rose.  “I think I am well enough now to relieve you of my intrusion,” she said.

“You will not be allowed to leave the hermit’s cell till you have finished the cracker and the milk,” affirmed the man.  “I only regret that I can’t keep up the character by offering you locusts and wild honey.”

“At least don’t think it necessary to stay here with me,” said Miss Durant, as she dutifully began to eat and drink again.  “If—­oh—­the operation—­How is Swot?”

“Back in the ward, though not yet conscious.”

“And the operation?”

“Absolutely successful.”

“Despite my interruption?”

“Another marvel to us M.D.’s is the way so sensitive a thing as a woman will hold herself in hand by sheer nerve force when it is necessary.  You did not faint till the operation was completed.”

“Now may I go?” asked the girl, with a touch of archness, as she held up the glass and the plate, both empty.

“Yes, if you will let me share your carriage.  Having led you into this predicament, the least I feel I can do is to see you safely out of it.”

“Now the hermit is metamorphosing himself into a knight,” laughed Constance, merrily, “with a distressed damsel on his hands.  I really need not put you to the trouble, but I shall be glad if you will take me home.”

Once again the doctor put his overcoat about her, and they descended the stairs and entered the brougham.

“Tell me the purpose of all those instruments I saw in your room,” she asked as they started.

“They are principally for the investigation of bacteria.  Not being ambitious to spend my life doctoring whooping-cough and indigestion, I am striving to make a scientist of myself.”

“Then that is why you prefer hospital work?”

“No.  I happen to have been born with my own living to make in the world, and when I had worked my way through the medical school, I only too gladly became ‘Interne’ here, not because it is what I wish to do, but because I need the salary.”