there are no exceptions to the law of gravity. If the blood ran down the face towards the chin, the face must have been upright at the time; and if the blood trickled from the front to the back of the head, the head must have been horizontal and face upwards. But the man when he was seen by the engine-driver, was lying face downwards. The only possible inference is that when the wound was inflicted, the man was in the upright position—standing or sitting; and that subsequently, and while he was still alive, he lay on his back for a sufficiently long time for the blood to have trickled to the back of his head."
"I see. I was a duffer not to have reasoned this out for myself," I remarked contritely.
"Quick observation and rapid inference come by practice," replied Thorndyke. "What did you notice about the face?"
"I thought there was a strong suggestion of asphyxia."
"Undoubtedly," said Thorndyke. "It was the face of a suffocated man. You must have noticed, too, that the tongue was very distinctly swollen and that on the inside of the upper lip were deep indentations made by the teeth, as well as one or two slight wounds, obviously caused by heavy pressure on the mouth. And now observe how completely these facts and inferences agree with those from the scalp wound. If we knew that the
