are rare in those in which the insensible contractility, is so very obscure, as to be only at the degree necessary for nutrition. It is to this that must be referred the infrequency of acute inflammations of this system. As this affection is frequent in the cutaneous, the serous, the mucous systems, &c. so this system, whose functions require but little insensible organic contractility, presents it rarely. Those who open many dead bodies know, that the texture of the heart is hardly ever found inflamed. Nothing is more common than phlegmasia of the external or serous membrane, and of the internal or mucous membrane of the stomach, the intestines, &c.; but nothing is more obscure and less frequently seen than that of their fleshy tunic. In rheumatism, there is sometimes when the pains cease around the joints, violent cholics, spasmodic vomitings even, indices perhaps of an acute affection of the fibres of the stomach or intestines; but we never find marks of these affections; we do not see the muscular texture exhibiting the bright red of the inflamed mucous, cutaneous and serous organs; or at least I have never observed it. Physicians have not paid sufficient attention to the difference of inflammations according to the difference of systems; but especially they have not sufficiently observed that this difference accords perfectly with that of the insensible organic contractility; that where this vital force is most characterized, inflammations have the greatest tendency to take place, because it is this which presides over their formation; because these affections suppose its increase; as convulsions suppose the increase of animal contractility, as vomitings, accelerated pulsations of the heart, suppose that of organic contractility, &c. I cannot repeat it too much, that the most frequent diseases in each system, put always in action, raise or diminish the predominant vital force in that system. It is a new pathological view, that may be fruitful in results. ARTICLE FOURTH. PHENOMENA OF THE ACTION OF THE MUSCULAR SYSTEM OF ORGANIC LIFE. These phenomena are, as in the preceding system, relative to the state of contraction or to that of relaxation. I. _Force of the Contractions._