"A person, then, may be sane as regards some things, and insane as regards others?"

"Undoubtedly."

"Would the fact that a person had at one time been confined in an asylum, and had occasional lapses from sanity afterward, tend to prove that he was insane at the time of committing a crime?"

"It would tend to prove it very strongly; especially if the circumstances under which the crime was committed were related in any way to the cause of the insanity."

He paused a moment in deep thought.

"I cannot go that far," he said slowly, at last. "And yet—and yet—it may be that you've hit upon the clue, Mr. Lester. I must have time to think it over. Will you come to see me this evening?"

"Gladly," I said; "I only hope I can be of service."

"Thank you. I shall look for you between seven and eight. It may be that I shall have something to tell you."

I watched him as he left the room, with a curious mixture of emotions. What was it he would have to tell me? Who was it was insane? Was it——

And suddenly I seemed to catch a glimmer of the truth; I felt that, however slowly and uncertainly, I was at last groping toward the light.