3d. The cerebral nerves and brain have evidently no connexion with the sympathies that put in action sensible organic contractility or irritability. If they had, the affected organ would first act upon the brain, and this would react upon the involuntary muscle; thus, when tickling produces vomiting, there would be an action of the skin upon the brain, and of the brain upon the stomach. Now the brain never exerts any influence upon the involuntary muscles; whatever be the irritation that the nerves experience which go to them, the muscles remain unaffected. Then although the brain may be sympathetically affected, it does not react upon the involuntary muscles; the cerebral nerves then have no connexion with the sympathies of sensible organic contractility. The continuity of the membranes is not a more substantial cause, and this is the proof of it. We know that by irritating the uvula, the stomach heaves; now as the mucous surface of the one and the other is the same, we might attribute this sympathetic phenomenon to this circumstance. I have then made a wound in the side of the neck of a dog; taken hold of the œsophagus and cut it transversely; the uvula has been afterwards irritated; the dog, notwithstanding the interruption of continuity, made efforts to vomit as before. Let us acknowledge then that we do not know the cause of the sympathies of sensible organic contractility. 4th. As much may be said of the sympathies of organic sensibility and insensible contractility. We have proved that the nerves have no influence upon these two properties; that by acting upon them we neither increase or diminish them in any manner, and that their diseases do not disturb the functions over which these properties preside. Then when they are sympathetically disordered, the nerves appear to have no connexion with these phenomena. Thus, 1st, every sympathetic exhalation, as the sweats of phthisical patients, certain serous infiltrations that take place almost instantaneously, &c.; 2d, all secretions of the same kind, as those which appear in a number of diseases afford us examples of them, &c.; 3d, all analogous absorption, the three functions over which the preceding properties preside, are evidently unconnected with the nervous influence of animal life. I shall say the same of the cellular, vascular influences, &c. Certainly we have no data, by which we can explain how these means of communication produce sweat when the lungs are affected, and saliva in the mouth when the membrane of the palate is irritated, &c.