2713. If the nerve becomes involuntarily negative, then originates spasm.
2714. If the nerve continue morbidly indifferent, then paralysis originates.
Nervous and Vegetative Systems.
2715. The second great system is the tegumentary formation. In this too its ordinary functions occur, such as secretion, evaporation, nutrition, elevation or depression of heat without nervous influence; or they occur while the nerve only acts indifferently.
2716. But if it acts by polarizing, as in the muscular motion, then the tegumentary processes are at once changed. What is material becomes extinguished, and the simply Irritable is manifested in the cells, capillary vessels, and so on.
2717. The process of temperature becomes thereby instantly changed, because the decomposition is changed. The heat is increased by the rapid suppression of the evaporation; it is diminished by the rapid increase of the latter.
2718. The art and manner in which the nerves act upon what is vegetable, is consequently an elevation of this Vegetable to what is animal. It must resign its processes, and simply undertake those of motion. Exactly the same takes place in the secernent organs. They perform their offices themselves through the galvanic tension of the vessels. But if the nerve act upon them they secrete more powerfully, and exactly from the same cause whereby the muscle is self-moved. Thus, if the nerve operate feebly, whereby it is in an irritable state, or if its action be wholly withdrawn, then the secretion will become less.
2719. The more irritable the nerves are, by so much the more animal does the vegetable organism, or the splanchnic system, therefore become; so much the less is it produced on the mass.
2720. Irritable animals and men are therefore meagre or lean. The two cases are uniformly related to each other. Lean men are irritable, not perhaps because the nervous ends are not covered with fat, such as there might be over the integument, the ear, the tongue, nose, &c., but, because where the nutritive process is inactive, what is animal necessarily preponderates. There are consequently three kinds of nervous actions, or phenomena, though all nervous activity in entire systems is similar, or but one. The difference is only derived from the organ upon which the nerves act. There are, consequently, no special nerves of sensation, motion and secretion; or such, forsooth, as have only one of these offices to take care of. Thus, were a nerve of sensation to be prolonged or drawn over a muscle, it would excite motion, and in the case of the liver, secrete bile, &c.
Mesmerism.