means of proving
his innocence."

"Yes. I suppose so," she rejoined in a dejected whisper. "At any rate we
shall soon know now."

At this moment the usher's voice was heard calling out the name of the
first witness for the defence.

"Edmund Horford Rowe!"

A keen-looking, grey-haired man, with a shaven face and close-cut
side-whiskers, stepped into the box and was sworn in due form.

"You are a doctor of medicine, I believe," said Anstey, addressing the
witness, "and lecturer on Medical Jurisprudence at the South London
Hospital?"

"I am."

"Have you had occasion to study the properties of blood?"

"Yes. The properties of blood are of great importance from a
medico-legal point of view."

"Can you tell us what happens when a drop of blood--say from a cut
finger--falls upon a surface such as the bottom of an iron safe?"

"A drop of blood from a living body falling upon any non-absorbent
surface will, in the course of a few minutes, solidify into a jelly
which will, at first, have the same bulk and colour as the liquid
blood."

"Will it undergo any further change?"

"Yes. In a few minutes more the jelly will begin to shrink and become
more solid so that the blood will become separated into two parts, the
solid and the liquid. The solid part will consist of a firm, tough jelly
of a deep red colour, and the liquid part will consist of a pale yellow,
clear, watery liquid."

"At the end, say, of two hours, what will be the condition of the drop
of blood?"

"It will consist of a drop of clear, nearly colourless liquid, in the
middle of which will be a small, tough, red clot."

"Supposing such a drop to be taken up on a piece of white paper, what
would be its appearance?"

"The paper would be wetted by the colourless liquid, and the solid clot
would probably adhere to the paper in a mass."

"Would the blood on the paper appear as a clear, red liquid?"

"Certainly not. The liquid would appear like water, and the clot would
appear as a solid mass sticking to the paper."

"Does blood always behave in the way you have described?"

"Always, unless some artificial means are taken to prevent it from
clotting."

"By what means can blood be prevented from clotting or solidifying?"

"There are two principal methods. One is to stir or whip the fresh blood
rapidly with a bundle of fine twigs. When this is done, the fibrin--the
part of the blood that causes solidification--adheres to the twigs, and
the blood th