Pharmacologia / Fourth American, from the Seventh London Edition

by John Ayrton Paris

[246]. It has been observed under the history of Emetics (p. 84), that in cases of profound intoxication, or in those of violent wounds and contusions of the head, vomiting will not take place, however forcibly the stomach may be goaded by an emetic, whereas if the brain be only partially influenced, as by incipient intoxication, or by a less violent blow on the head, its irritability is increased instead of being paralysed, and that vomiting under such circumstances is excited by the slightest causes; just so is it with regard to Narcotics, a powerful dose so paralyses the nervous system, that the stomach cannot be made to reject its contents, as every one must have observed in cases of narcotic poisoning, while smaller doses, like lesser injuries of the head, dispose the stomach to sickness.

[247]. Sir Gilbert Blane has advanced an ingenious hypothesis to explain the cause of the fœtid breath of persons under the influence of mercury; which might perhaps also shew why certain remedies are rendered more efficient by combination with mercury. One of the active effects of mercury, says Sir Gilbert, is to alter the natural sensibility of the Lacteals, so that when under its influence, they absorb indiscriminately that which is excrementitious and nutritive; hence the smell of the breath, since the fœtid particles are carried into the circulation, and thrown off in the halitus of the lungs, or by the salivary glands, in consequence of the mouth of the lacteals losing that selecting tact, whereby in their sound state they reject whatever is offered to them, except the chyle. Now if mercury acts as the “Soporata Offa” to the lacteals, it is evident that its combination with active matter may, on some occasions, facilitate the absorption of the latter.

[248]. In some cases, however, the energy of an active bitter would seem to be diminished by an alkali; and it may therefore be more prudent to administer such substances at different periods. I apprehend that the powers of Squill are thus invalidated by a fixed alkali.

[249]. The Arabian and Greek physicians scarcely noticed the leaves, but always employed the pods of Senna; a fact which will explain the operation of this plant, as observed by them.

[250]. Mac Culloch on Wine. Edit. 2. p. 42.

[251]. If the facts stated in this section be true, we are bound to recognise two orders of medicinal elements,—the one comprehending those that possess an inherent and independent activity,—the other, those that are in themselves inert, but which are capable of imparting impulse and increased energy to the former when combined with them. As this is a new view of the subject of vegetable combinations, no apology is necessary for the introduction of new terms for its explanation; I therefore propose to designate the former of these Substantive, and the latter, Adjective constituents. When the structure of vegetable remedies shall have been thoroughly examined upon this principle of combination, much medicinal obscurity will be removed, and probably some pharmaceutical improvements of value suggested; at all events it will teach a lesson of prudent caution to the pharmaceutic chemist; it will shew the danger of his removing this or that element from a vegetable compound, merely because he finds, upon its separation, that it is inert. I dwell the more upon this point, because I feel that there never was a period in the history of medicine, at which such a caution was more necessary; for while the poly-pharmacy of our ancestors has driven the physician of the present day into a simplicity of prescription that on many occasions abridges his powers and resources, the progress of chemical knowledge has diffused through the class of manufacturing chemists a bold spirit of adventure and empiricism,—a mischievous propensity to torture our best remedies, in order to concentrate or extract the parts which they consider to constitute their essential ingredients.

A Memoir has lately been presented to the Philomatic Society of Paris, by M. Robiquet, on the subject of Aroma, which affords some important analogies in proof of the law of combination, which I am now endeavouring to elucidate. From the experiments of this laborious chemist it would appear, that odours are not as Fourcroy supposed, the effect of the simple solution of certain bodies in air, but that for their developement, some third body (coinciding in its office with my Adjective constituent) possessing in itself none of the characteristic odour, is absolutely necessary as an intermede, varying in its nature according to that of each odorous body, in the same way that the mordant requires to be varied by the dyer, according to the nature of the colouring matter which it is intended to fix on the cloth;—thus Ambergris has in itself very little odour, but the addition of Musk developes a very strong and decided one; this also happens in a less degree with Lavender, and the perfumers therefore add a small quantity of musk to the distilled water of this plant. In other cases, Ammonia lends, as it were, its volatility to bodies, the odour of which without such an auxiliary, would be scarcely sensible; this is exemplified by the practice of perfumers exposing their musk and other substances to the atmosphere of privies when they lose their power: (Paul Amman: Manduct: ad Mat: Med:) so again in order to give pungency to snuff it is made to suffer the commencement of fermentation, in which case ammonia is generated; and it is a curious fact that the odour of the best snuff may be destroyed by mixing with it a little tartaric acid, by which its ammoniacal salt is neutralized. In some instances the adjective ingredient seems to be Sulphur, as in the essential oils of some cruciform plants, and particularly in that of mustard seed, for M. Robiquet found that this oil lost its odour by being kept in contact with a metallic surface, and that an inodorous oil remained, while the metal became a sulphuret: perhaps, adds M. Robiquet, it may be sometimes necessary for the full and exquisite developement of odour in these bodies to add another vehicle, thus the addition of a little Acetic acid heightens the odour of Mustard.

Iron has little, or no odour; but when volatilized with hydrogen, its odour is very powerful. The smell of copper and brass must depend upon some circumstance not well understood.

[252]. Astruc, and other practitioners of the same school, always premised a mercurial course with venesection: it is probable that many of the anomalies observed in the modern application of this remedy may have arisen from an inattention to the diet of those who are under mercurial influence. Mercury is in itself a most powerful stimulant, and ought therefore to be accompanied with depletion and low diet; besides which, the experiments of Majendie have shewn how greatly such a state of the system will expedite the effects of the mercurial remedy.

[253]. Dr. Eberle, of Philadelphia, in a work lately published, has quoted the above passage, and remarks, that he has long been acquainted with the fact which it announces; although he proposes to account for it by a different train of reasoning; he considers that Nauseants encourage mercurial ptyalism, by favouring an afflux to the salivary glands. The learned author must allow me to congratulate him upon this fortunate discovery; unless his patients be blessed with as much apathy as was ever assumed by the Gilbertine order of Benedictines, he need never in future despair of influencing them by mercury. He has only to condemn the refractory to meagre fare, and then to tantalize them, as poor Sancho was, in his government, with the sight, or rather smell, of a savoury dish, and he will without doubt secure his object,—but, to be serious, if Dr. Eberle’s views be correct, how will he explain the modus operandi of fear, as related in the text? for the tendency of fear is to diminish the salivary secretion, as will be hereafter mentioned.