Year: 1874

As you well know, Dr. Brown-Se- quard tells us, the blood circulates from the arteries to the veins, and Prof. Draper, of New York, has perfectly we'll proved that the chemical changes occurring in tissues must be cause of activity of the circulation. But there are many other facts besides those he knew, which show that when we irri- tate nerve, if there is more blood in the part where that nerve goes, it is not because that nerve goes to blood vessels, and affects them by dilating them, but because of the direct trans formation of nerve force into chemical force producing an attraction of blood. A great many facts indeed show us that circulation will go on without an inn pulse from the heart. In plants the circulation proceeds from chemical changes without any heart at all with out any power that pushes the liquids forward.

 In foetal monsters in our own species there are cases in which the monster had no heart, and in which the commu- nication of it's circulatory system with that of the almost half child with which it was connected, was too slight for the circulation to go on if we were to look upon the heart as the only organ pro- dtcing circulation. Besides, in em- bryos, in animals at certain degree of their development form the ovun, cir culation takes place while the heart is not yet formed. And we may say that instead of the heart being the only organ that serves for circulation, that, on the contrary, the heart is formed by asr 1ofS n give it a form of organization, and helps to give it @ function when 1t has accomplished its organization.

 long ago made an experiment. with frogs, consisting ill making a section of the ventric1e of tue heart, dividing it so as to do away with more than two thirds of the length of that part. After time a clot is formed there which unites the lips of the cut, and the circu- lation goes on with part of the ven tricle, which is so small indeed that there is hardly an impulse coming from it. There is passage, however, for the blood there, and that is all that is necessary, that the great cause of cir culation, which is attraction, may be accomplished in every tissue through life. Even in our own species 1t has been my lot to see. one case, that of lady, in which the heart was almost en- tirely destroyed by fatty deposition. The heart in this case had very lite ac' tion, if any, but still life persisted fol some time. In appearance there was a state of health, until suddenly one day death occurred.

 There is on record the case of man who for three days had had no beating whatever of the heart and who, never theless, had had circulation. He had had no pulse---the beating of the pulse depending on the heart-but the blood was circulating, and life was maintained all the time. Therefore, although would not say certainly that the heart is useless organ, it is certainly by fal less important than it was considered to be, a great deal of the work of circu lation being due to the attraction tha tissues exert on the blood. That at traction is increased by certain nerves and thereby circulation is considerably increased, sometimes locally to mos wonderful extent, by an irritation of the nervous system. In cases of lnhamma tion we see this very plainly. Where the inflammation exists inside of the cranium, we find that the carotid artery beats with tremendous violence. Some times we find an enormous increase o pulsation in the arteries of the temple As we find in such cases that the heart as indicated by the pulse in the wrist is not beating with much more force than usual, we must conclude that there is considerable irritation and al inflammation in the membrane of the brain or the brain itself.