society thus formed had its rules intended to aid the progress of science. A few years before, a Benedictine monk, Robert des Gabets, had preached a sermon there on transfusion of the blood. The king's councillor took interest in a discovery of which he foresaw the range, and gave the new experimenter the support of his influence.
"The first trial," Denis says, "was made on a young man, fifteen or sixteen years old. This youth was attacked by a slow fever, for which the doctors had bled him twenty times. He had become dull and sleepy, from the treatment, to the point of stupidity. Some little warmth was felt during the operation. Eight ounces of blood were taken from him, and arterial blood from the carotid of a lamb was immediately introduced by the same opening. He got up about ten o'clock, dined with excellent appetite, and went to sleep at four in the afternoon. He bled slightly from the nose."
This operation having succeeded, Denis tried a second, but more from curiosity than necessity this time. The author relates it himself as concisely as before. "The transfusion was effected upon a chair-porter, of vigorous constitution, forty-five years old. Ten ounces of blood were taken from him, and lamb's blood substituted. The man complained of no pain during the operation, and was delighted beyond measure with the new invention, which seemed to him very ingenious. When it was all over, he declared that he never felt better. Employment offering about noon, he carried a sedan as usual for the rest of the day. Next day he begged that no one but himself might be taken as the subject of new experiments."
Three years before, transfusion of blood had been practised by Lower in England, but only on dogs. Denis repeated with these animals the experiments he had made on men. These were varied in the most interesting ways. He not only transfused the blood of one animal into the veins of another; but, from the 8th to the 14th of March, in 1667, he caused the same blood to pass into three different dogs successively. Granting the correctness of the views then prevalent, he then realized the famous Pythagorean fable of the transmigration of souls. The experimenter was also bent on making his discoveries generally known, proposing to make trials in public, and, for this purpose, he fixed for the first day of his lectures "Saturday, the 19th of March, of the same year, at two in the afternoon, on the quay of the Augustins." History does not inform us whether Denis carried out his plan; but the Journal des Savants gives a tedious account of a controversy that broke out more fiercely. In this previous war of ideas, facts are neglected and forgotten, arguments are only dealt with, and they control opinions. Denis declared at the outset that he would depend solely on experiment; but, at the same time, with a contradiction explained by the tendencies of the times, he comes forth into the scientific arena with the usual weapons—he discusses. The works devoted to this warm contest are all inserted in the Journal des Savants;