General therapeutics and materia medica (Volume 2).

  • Dunglison, Robley, 1798-1869.
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: General therapeutics and materia medica (Volume 2). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    moment, without fear of debility resulting. It has been already seen, that it isthe use of diffusible stimuli, which is alone followed by corresponding depression. Bitter extractive appears to be the great tonic principle of most of the vegetable tonics ; aided, in some, by the presence of aromatic oil—which renders them more stimulating tonics—in others, by the presence of one or both of the great astringent principles of vege- tables. This bitter extractive is not affected by heat; but the aro- matic oil is, provided the boiling temperature be applied for some time. Decoction is, therefore, an improper mode of preparation, where the object is to retain the aromatic property. Infusion is the form most commonly prescribed, and hence the pharmacopoeias con- tain officinal infusions of all the principal vegetable tonics. Dr. Thomson asserts, that Dr. Chapman, and—following him— Dr. Paris, attempt to prove, that bitterness is essential to tonics; or, in other words, that it is the tonic principle ; but in this, he does those writers injustice. The latter gentleman affirms, that the tonics, derived from the vegetable kingdom, are generally bitter ; — whilst the former expressly says : — Concerning the element, which gives the tonic power, some difference of opinion has been entertained. Cullen supposed it to be the same quality as that of bitterness. But though it holds to a considerable extent, there would seem to be no necessary connexion in all cases. Exceptions at least are not want- ing, as we see very strikingly in opium and digitalis, which are bitter, though not tonic ; and, conversely, in many of the metallic articles, which, though tonic, are not bitter in the slightest degree. Nor do we think Dr. Thomson more accurate in his opinion, that part of all the vegetable tonics are [is] digested in the stomach, and the principle, whatever it is, which produces their tonic influence, is thus separated from the other parts ; and consequently it is enabled to act with more energy upon the nerves of the stomach. This explanation can scarcely apply to infusions of vegetable substances, and still less to the active principles of such substances ; nor can it well apply to them when given in the solid form, as in the state of powder, in which the active principle is combined with little more than lignin or woody fibre, in many cases. It is but necessary, that the fluids of the stomach, or any fluids, should come in contact with the substance in order to extract its tonic virtue ; but nothing like digestion — as applied to the physiological process to which alimen- tary matters are subjected — is necessary. Bitter extractive, as Dr. Paris has remarked, is a great natural tonic. It appears to pass through the body without suffering any diminution in its quantity, or change in its nature. No cattle will thrive upon grasses, which do not contain a portion of this principle ; a fact, which is considered to have been proved by the researches of Mr. Sinclair, gardener to the Duke of Bedford, in his Hortus Gra~ mineus Wobumensis where he remarks, that if sheep be fed on yellow turnips, which contain little or no bitter principle, they in-