It was well along toward midnight before the hasty conference had been gathered; besides Mrs. Godwin, Salo Kahn, and ourselves, the three Elmores, Kilgore, and Hollins.

Strange though it was, the room seemed to me almost to have assumed the familiar look of the laboratory in New York.  There was the same clutter of tubes and jars on the tables, but above all that same feeling of suspense in the air which I had come to associate with the clearing up of a case.  There was something else in the air, too.  It was a peculiar mousey smell, disagreeable, and one which made it a relief to have Kennedy begin in a low voice to tell why he had called us together so hastily.

“I shall start,” announced Kennedy, “at the point where the state left off—­with the proof that Mr. Godwin died of conine, or hemlock poisoning.  Conine, as every chemist knows, has a long and well-known history.  It was the first alkaloid to be synthesised.  Here is a sample, this colourless, oily fluid.  No doubt you have noticed the mousey odour in this room.  As little as one part of conine to fifty thousand of water gives off that odour—­it is characteristic.

“I have proceeded with extraordinary caution in my investigation of this case,” he went on.  “In fact, there would have been no value in it, otherwise, for the experts for the people seem to have established the presence of conine in the body with absolute certainty.”

He paused and we waited expectantly.

“I have had the body exhumed and have repeated the tests.  The alkaloid which I discovered had given precisely the same results as in their tests.”

My heart sank.  What was he doing—­convicting the man over again?

“There is one other test which I tried,” he continued, “but which I can not take time to duplicate tonight.  It was testified at the trial that conine, the active principle of hemlock, is intensely poisonous.  No chemical antidote is known.  A fifth of a grain has serious results; a drop is fatal.  An injection of a most minute quantity of real conine will kill a mouse, for instance, almost instantly.  But the conine which I have isolated in the body is inert!”

It came like a bombshell to the prosecution, so bewildering was the discovery.

“Inert?” cried Kilgore and Hollins almost together.  “It can’t be.  You are making sport of the best chemical experts that money could obtain.  Inert?  Read the evidence—­read the books.”

“On the contrary,” resumed Craig, ignoring the interruption, “all the reactions obtained by the experts have been duplicated by me.  But, in addition, I tried this one test which they did not try.  I repeat:  the conine isolated in the body is inert.”

We were too perplexed to question him.

“Alkaloids,” he continued quietly, “as you know, have names that end in ‘in’ or ’ine’—­morphine, strychnine, and so on.  Now there are two kinds of alkaloids which are sometimes called vegetable and animal.  Moreover, there is a large class of which we are learning much which are called the ptomaines—­from ptoma, a corpse.  Ptomaine poisoning, as every one knows, results when we eat food that has begun to decay.