Ten years ago, prior to the discovery of the serum test, it would not have been possible, except in the cases where the blood corpuscles could be examined, to prove or disprove this except by corroborative evidence. There was no chemical means of determining whether an old blood stain had been caused by the blood of a man or that of an animal. Taylor, writing in 1844 upon this point, observes: "Some French medical jurists state that by mixing fresh blood with a certain portion of sulphuric acid and agitating the mixture with a glass rod a peculiar odour is evolved which differs in the blood of man and animals, and also in the blood of the two sexes. This odour, it is said, resembles that of the cutaneous exhalation of the animal, the blood of which is the subject of experiment. They have hereby pretended to determine whether any given specimen of blood had belonged to a man, a woman, a horse, sheep, or fish. Others pretend that they have been able to identify the blood of frogs and fleas!" As Taylor pertinently observes of this: "There is probably not one individual among a thousand whose sense of smelling would be so acute as to allow him to state with undeniable certainty, from what kind of animal the unknown blood had really been taken. Any evidence short of this would not be received in an English court of law." On the first occasion upon which scientific evidence as to the difference between the blood of man and of animals was given in a criminal trial the remarks made by the judge (Lord Chief Justice Cockburn) to the jury showed that he was sceptical as to the powers claimed by the chemical witness of distinguishing between different kinds of blood. In this case, which was tried at the Taunton Assizes, in 1857, a man had been found with his throat cut, and collateral evidence pointed to a man named Nation being the murderer. When he was arrested he was found to have a knife upon him on which were stains that appeared to be blood, but the prisoner accounted for these by saying that he had recently been cutting raw beef with the knife. The chemical evidence, however, went to prove that coagulation of the blood had not occurred until after it had come into contact with the knife, or, in other words, that the blade had been plunged into living blood. Moreover it was stated by this witness that the blood could not have been that of an ox, pig or sheep, since the corpuscles were smaller than those of human blood, whereas the corpuscles of the blood upon the knife were of the same dimensions as those of human blood. The relative sizes of human corpuscles compared with those of the animals mentioned were stated to be as fifty-three to thirty-four in the case of the ox; as fifty-two to thirty-four in sheep's blood; and as forty-five to thirty-four in pig's blood.