Jasper Cole nodded

Jasper Cole nodded.
"I am perfectly aware that he was murdered by your friend, Mr. Merrill," he said.
"I suggest," said Saul Arthur Mann calmly, "that you know the murderer, and you know the murderer was _not_ Frank Merrill."
Jasper made no reply, and a faint smile flickered for a second at the corner of his mouth, but he gave no other sign of his inward feelings.
"And the other point you wish to raise?" he asked.
"The other is a more delicate subject, since it involves a lady," said the little man. "You are about to be married to Miss Nuttall."
Jasper Cole nodded.
"You have obtained an extraordinary influence over the lady in this past few months."
"I hope so," said the other cheerfully.
"It is an influence which might have been brought about by normal methods, but it is also one," Saul Arthur leaned over and tapped the table emphatically with each word, "which might be secured by a very clever chemist who had found a way of sapping the will of his victim."
"By the administration of drugs?" asked Jasper.
"By the administration of drugs," repeated Saul Arthur Mann.
Jasper Cole smiled.
"I should like to know the drug," he said. "One would make a fortune, to say nothing of benefiting humanity to an extraordinary degree by its employment. For example, I might give you a dose and you would tell me all that you know; I am told that your knowledge is fairly extensive," he bantered. "Surely you, Mr. Mann, with your remarkable collection of information on all subjects under the sun, do not suggest that such a drug exists?"
"On the contrary," said "The Man Who Knew" in triumph, "it is known and is employed. It was known as long ago as the days of the Borgias. It was employed in France in the days of Louis XVI. It has been, to some extent, rediscovered and used in lunatic asylums to quiet dangerous patients."
He saw the interest deepen in the other's eyes.
"I have never heard of that," said Jasper slowly; "the only drug that is employed for that purpose is, as far as I know, bromide of potassium."
Mr. Mann produced a slip of paper, and read off a list of names, mostly of mental institutions in the United States of America and in Germany.
"Oh, that drug!" said Jasper Cole contemptuously. "I know the use to which that is put. There was an article on the subject in the _British Medical Journal_ three months ago. It is a modified kind of 'twilight sleep'--hyocine and morphia. I'm afraid, Mr. Mann," he went on, "you have come on a fruitless errand, and, speaking as a humble student of science, I may suggest without offense that your theories are wholly fantastic."
"Then I will put another suggestion to you, Mr. Cole," said the little man without resentment, "and to me this constitutes the chief reason why you should not marry the lady whose confidence I enjoy and who, I feel sure, will be influenced by my advice."
"And what is that?" asked Jasper.
"It affects your own character, and it is in consequence a very embarrassing matter for me to discuss," said the little man.
Again the other favored him with that inscrutable smile of his.