Authors have considered sympathies in too loose a manner. Some have admitted, others have rejected the intermediate office of the brain; some have not pronounced upon it. All would be agreed, if instead of attempting to resolve the question in a general manner, they had distinguished the sympathies according to the vital forces, of which they are only aberrations and irregular developments; they would have seen, that in the animal sympathies of contractility, the cerebral action is essential; for we cannot conceive of any contractility of this species, without the double influence, nervous and cerebral, upon the muscles; that on the contrary, in the organic sympathies of contractility, the action of the brain is nothing; the affected organ acts directly and without any thing intermediate upon that which contracts sympathetically. When the heart, the stomach, the intestines, &c. move, when the parotid and other glands increase their action by the sympathetic influence of an affected organ, certainly this organ does not act first upon the brain; for it would then be necessary that this should re-act upon those that contract; now it would not be able to influence them except by the nerves, since it is only by these that it is united to them; but all experiments and all facts prove as we shall see, that the brain has not by this means any influence over the organs with involuntary motions; then the action is direct and there is nothing intermediate. There are sympathetic motions like the natural ones; the sensible and insensible contractilities are constantly brought into action by a direct stimulus applied to the organ, whilst that the animal contractility is never exercised but by the cerebral stimulant, which itself requires a cause, either sympathetic or direct, in order to act upon the muscles. Next to animal contractility, the sensibility of the same nature is the most often brought sympathetically into action in the animal muscular system. The lassitude, wandering pains, sensation of weight and stretchings that are felt in the limbs in the beginning of many diseases, are phenomena purely sympathetic, in which this property enters into action in the muscles. At advanced periods of many other affections, these sympathetic troubles are also very remarkable, but less in general than at the beginning. The organic properties are for the most part rarely sympathetically in action in the species of muscles of which we are treating. Besides, if they are so, we can hardly judge of it, because no sign points it out to us. The sweat in the skin, the secreted fluids in the glands, the fluids exhaled upon many of the surfaces, are general results which indicate to us the sympathetic derangements of the organic sensibility and of the insensible contractility of the same species. In the muscles, we have not the same means of knowing these alterations. _Characters of the Vital Properties._