one nine-thousandth of an inch in breadth. And yet, minute as these crystals are, this discovery is of immense medico-legal importance. Crime may now be traced by blood-crystals."
He displayed on his table a number of enlarged micro-photographs. Some were labelled, "Characteristic crystals of white man's blood"; others "Crystallisation of negro blood"; still others, "Blood-crystals of the cat."
"I have here," he resumed, after we had all examined the photographs and had seen that there was indeed a vast amount of difference, "three characteristic kinds of crystals, all of which I found in the various spots in the kitchen of Mr. Pitts. There were three kinds of blood, by the infallible Reichert test."
I had been prepared for his discovery of two kinds, but three heightened the mystery still more.
"There was only a very little of the blood which was that of the poor, faithful, unfortunate Sam, the negro chef," Kennedy went on. "A little more, found far from his body, is that of a white person. But most of it is not human blood at all. It was the blood of a cat."
The revelation was startling. Before any of us could ask, he hastened to explain.
"It was placed there by some one who wished to exaggerate the struggle in order to divert suspicion. That person had indeed been wounded slightly, but wished it to appear that the wounds were very serious. The fact of the matter is that the carving-knife is spotted deeply with blood, but it is not human blood. It is the blood of a cat. A few years ago
