Читать книгу The Action of Medicines in the System - Frederick William Headland - Страница 10

The details of this arrangement, to which I shall at present venture to object, are, first, the multiplicity of classes, and secondly, the inclusion of certain medicines in the division of Cerebro-spinals.

Three of the classes seem to be superfluous, and only tend to confuse. There is a class of Pneumatics, acting on the respiratory organs. But Expectorants are found elsewhere among Eccritics; and those medicines which influence the nerves of the lungs, among Neurotics. The same with Cœliacs; for Cathartics, found among Eccritics, are the most important medicines acting on the intestines. Genetics contain medicines which control the uterine and sexual systems, which may all be reckoned among Neurotics. And yet this multiplicity of names is consistently employed in carrying out the principle of this classification, which is, to arrange according to the different parts of the system all substances which have any tendency to act on those parts.

Dr. Pereira makes four orders of Cerebro-spinals; three include different kinds of Narcotics, very minutely subdivided; another is called Cinetics. They affect the muscular system; but it is altogether an assumption to assert that these medicines, Astringents and Tonics, do so by influencing the nerves. As to Astringents, it appears that they do not affect the nerves in any way, for which reason I shall have to make a separate class of them. For Tonics, there is great reason to suppose that in the first place they act on the blood; so that I cannot agree with Dr. Pereira, who ranks them among Neurotics. Emetics are classed by him among Eccritics; but it seems to me that their action is either external, and of an irritant nature, or when from the blood, that it is exerted upon the nerves of the stomach. The stomach is not, like most glandular organs, a simple emunctory, and it is affected by medicines in a different way. Whereas gland-medicines increase secretion, the chief action of Emetics is to cause an evacuation of the contents of the stomach by contraction of itself and of other muscles. All substances which touch the stomach cause the copious outpouring of a thin fluid by mere contact; yet we cannot for this reason call them medicines which tend to increase secretion. Emetics acting from the blood after absorption, as Tartar emetic, which generally influence at the same time either the lungs or the heart, parts supplied by the other branches of the Vagus nerve, which is distributed to the stomach, seem to me to be Specific Neurotics, probably acting on that nerve. So that in these points, as well as in some others, I am disposed to differ from Dr. Pereira.

It is apparent that in none of the classifications of this second kind is any mention made of the primary action or modus operandi of medicines in the cure of disease, as a necessary basis of such distinctions.