"Only by the size of the corpuscles. They are large and compressed on either side. It can be done only by means of a powerful microscope, and even with this aid none but an expert can tell. By submitting the blood to this test it was found to be human blood. This settled, the next thing of importance was to find out if the two specimens of blood bore any resemblance."
"Can you tell to a certainty whether two drops of blood come from the same body?"
"You cannot; but if they bear certain marks of resemblance the inference is pretty strong. You must bear in mind that the blood in both cases was taken from wood. That found in the trunk was diluted with water. After diluting the blood taken from the floor of the house sufficiently to make it of the same consistency, or as near as may be, with that from the trunk, we submitted them both to the microscopic test——"
"And found?"
"That the points of resemblance were marked. The pigment crystals were exactly alike."
"From which you inferred——"
"That the blood found in the trunk and that taken from the floor of the house came from the same person."
"Do you think, Doctor, that it is the blood of Dr. Cronin?"
"There is not the least doubt of it in my mind. It is almost certain that the doctor's body was in that trunk. If this is so, there can be little doubt that he met his death in the house on Ashland avenue."