The solubility of Morphia in acids explains why the administration of vinegar increases the powers of opium, (see page 135.) M. Majendie considers Morphia to produce a more purely soporose effect than opium, and that it is moreover exempt from the consecutive operation which so generally renders opium objectionable. This opinion, however, has not been confirmed by the trials made in this country; equally gratuitous is the assertion of the same physiologist, that by ringing changes on the salts of Morphia, its hypnotic effects may be kept up without increasing its dose.
As M. Majendie considers the after effects of opium to be independent of Morphia, it was necessary for him to point out the particular principle from which these noxious consequences arose, and he accordingly ascribed them to the Salt of Derosne, now more usually denominated Narcotine, and which may be entirely removed from the extract of opium by macerating it in sulphuric æther; and in this way, it is said, a preparation is obtained, which, like Morphia, is exempt from the occasional bad consequences of the common drug; but no satisfactory trials have as yet been made with it.
The Meconic acid, when separated from the residuum of the magnesian salt, as described above, does not appear to possess any medicinal activity. Its distinguishing chemical character is, that it produces an intensely red colour in solutions of iron oxidized ad maximum.
East India Opium is an inferior species;[[588]] it differs from Turkey Opium, in its texture being less compact, and much softer; its colour darker; its narcotic odour fainter, but combined with a strong empyreuma, and in its taste being more bitter, but less acrimonious. According to the experiments of Mr. A. T. Thomson, Turkey Opium contains three times more morphia than the East Indian variety. This latter, when triturated with water, is taken up without any residuum; hence it contains no gluten, but the sulphate of lime is more abundant, as appears from the relative proportion of precipitate produced by oxalic acid. The solution of the acetate of barytes, whilst it occasions no disturbance in the solutions of the Turkey variety, produces a copious precipitate with the East Indian.
Med. Uses. Are so well known that a few practical remarks will suffice.[[589]]
Chemistry, it appears, has developed the principle of its activity, and accumulated experience has established the value and importance of its medicinal applications, but Physiology is still unable to demonstrate the manner in which it produces its effects. It must be admitted that its primary operation is that of a powerful and diffusible stimulant, but it is immediately followed by narcotic and sedative effects, which are far greater than could have been inferred from the degree of previous excitement, and hence much keen controversy has arisen in the schools concerning its modus operandi, (see page 76.) In large doses, the primary excitement is scarcely apparent, but the powers of life are instantly depressed, drowsiness and stupor succeed, and when the dose is excessive, these are followed by delirium, stertorous breathing, cold sweats, convulsions, and apoplectic death. Its stimulant effects are apparent only in small doses, by which the energy of the mind,[[590]] the strength of the pulse, and the heat of the body, are considerably increased, but all the secretions and excretions, except the cuticular[[591]] discharge, are diminished; for example, the fæces of persons, after the use of opium, are not unfrequently clay-coloured, from the suspension of the biliary secretion; this circumstance suggests some important precautions with respect to its exhibition. Opium, when properly directed, is capable of fulfilling two great indications; 1st, of supporting the powers of life, and 2nd, of allaying spasm, pain, and irritation, and of blunting that morbid susceptibility of impression, which so frequently attends fever. Its use is contra-indicated in all cases where inflammatory action prevails, as in pulmonary affections, attended with an accelerated circulation and a dry hard cough.[[592]] It is employed by some of the oriental nations for the same purposes that we take spirituous potations: by the Turks especially, to whom our more generous beverages are prohibited by religious prejudice, opium is solicited to inspire courage, or to invigorate fortitude;—to soothe sorrow;—or to dissipate the remembrance of misfortune;—to awaken the fancy to more brilliant exertions; or to create that mild composure and serenity of feeling, which is desirable after the cares and solicitudes of an active, perplexing, and arduous scene: like spirituous liquors among other people, it is, in short, the support of the coward,—the solace of the wretched,—and the daily source of intoxication to the debauchee. Notwithstanding all this, spirit and opium are by no means parallel medicines; on the contrary, the latter substance offers the best remedy for the Mania a Potu, and in cases of habitual drunkenness from alcohol, where our wish is to abstract the spirit, but are for obvious reasons unable so to do, we may frequently alternate its use with that of opium, with considerable advantage. Many of the beneficial effects of this remedy are to be referred to its power of allaying irritability; Sir G. Blane has remarked, that in ill-conditioned ulcers in the West Indies, opium was found superior to all other internal medicines for producing a disposition to heal. Under the free use of it, such ulcers would in place of a sanious discharge produce a healthy puss succeeded by granulations and cicatrization. It appears to do this by suspending irritation, and perhaps by promoting absorption.
In combination, the medical powers of opium are wonderfully extended, so that there is scarcely a disease in which it may not, during some of its stages, be rendered useful. By diminishing the sensibility of the stomach and bowels, it becomes a valuable and efficacious corrigent to many important medicines, and thus frequently favours their absorption and introduction into the system, as for instance, in the exhibition of mercurial alteratives, (Form. 141,) and in certain diuretic combinations, (Form. 100, 106, 107, 110,) in combination with antimonials, and with ipecacuan, its narcotic powers are obviated, and sudorific results are obtained. See Pulv. Ipecac. co. (Form. 117, 119, 124, 125, 127, 130.) Forms of Exhibition. In substance, or under the form of tincture. When we wish to continue the operation of opium, and not to obtain its full effect at once, it may be advantageously combined with some substance capable of retarding its solution in the stomach, as gum resins. See Pilulæ and Form. 10, 11, 12, 13. A watery infusion, made by infusing powdered opium in boiling water, will often operate without producing that distressing nausea and head-ache which so frequently follow the use of this substance. With respect, however, to the best modes of correcting the operation of this remedy, see pages 160 and 162. Dr. Porter of Bristol has introduced to our notice a solution of opium in citric acid; his formula[[593]] for its preparation is subjoined, because I am of opinion that it merits the attention of the practitioner; I have lately submitted it to the test of experience, and it certainly possesses the merit of a powerful anodyne, operating with less disturbance than the more ordinary forms of this substance. I also take this opportunity of stating, that the pyroligneous acid manufactured by Beaufoy was used as a menstruum, and the effect of the solution was similar to that of Dr. Porter. When the stomach rejects altogether the internal exhibition of opium it may be successfully applied along the spine, by friction, with the camphor liniment; a piece of solid opium introduced into the rectum, or dissolved in some appropriate solvent, and injected as an enema, affords also considerable relief in spasmodic affections of the bowels, and in painful diseases of the prostate gland, or bladder, (Form. 9.) When thus introduced into the rectum, it cannot undergo that change which the digestive organs produce upon it, and consequently it is more uniform in its action than when presented to the stomach. Opium appears to be readily absorbed into the system, when applied to the surfaces of sores; considerable relief has been thus afforded to irritable stumps, after amputation, on which occasions, all the characteristic effects of opium have been produced upon the system, such as costiveness, head-ache, nausea, &c. Incompatible Substances. Oxy-muriate of mercury; acetate of lead; alkalies; infusions of galls, and of yellow cinchona. Orfila states that the decoction of Coffee is less energetic as an antidote, than the infusion. When we intend the opium to act as a sedative, we should not combine it with stimulants. The Edinburgh College certainly erred in this respect, when they made pepper an ingredient in their Pilulæ Opiatæ. In combination with vegetable acids, its narcotic powers are increased, in consequence of the formation of soluble salts with morphia.[[594]] When the opium however has passed out of the primæ viæ, vinegar and acids are then the best remedies for counteracting its effects; (see page 136.) Dose, must be varied according to the intention of the prescriber, the constitution of the patient, and the nature of the disease. A quarter of a grain, frequently repeated, will keep up its exhilarating influence; (Form. 15) from gr. j to ij acts as a narcotic; its power on the system soon becomes weaker; and from habitual use it is so much impaired that very large doses are required to produce its usual effects. Russell observes that the effects of opium on those addicted to its use, are at first obstinate costiveness, succeeded by diarrhœa and flatulence, with loss of appetite and a sottish appearance; the teeth decay, the memory fails, and the unhappy sufferer prematurely sinks into the grave. Officinal Prep. Gr. j of opium is contained in Confect. Opii. L. grs. 36. Elect. Opii. E. grs. 43. Elect. Catechu. E. grs. 193. (F.) Elect. Catechu. comp. D. grs. 199. (F.) Pil. Saponis cum opio. L. grs. 5. Pil. Opiat. E. grs. 10. Pil. e Styrace. D. grs. 5. Pulv. Corn. ust. cum Opio. L. grs. 10. Pulv. Cret. comp, cum Opio. L. grs. 40. Pulv. Ipecac. comp. L.E. grs. 10. (H.) Pulv. Kino. comp. L. grs. 20. (F.) Tinct. Opii. L. ♏︎19. Tinct. Camphor. comp. L. f℥ss. Tinct. Opii ammon. E. fʒj. Troch. Glycyrr. cum Opio. E. ʒj. Vinum Opii. L. ♏︎17. The Medicinal Dynameter will at once shew the quantity of opium in any proportion of the above preparations. Adulterations. The Turkey Opium, when good, is covered with leaves, and the reddish capsules of some species of rumex; the inferior kinds have none of these capsules adhering to them. It is frequently adulterated with the extract of liquorice; it should be regarded as bad when it is very soft and friable, of an intensely black colour, or mixed with many impurities, when it has a sweetish taste, or marks paper with a brown continuous streak when drawn across it, or when it melts like wax, and makes a yellow solution in water. It frequently happens that in cutting a mass of opium, bullets and stones have been found imbedded in it, a fraud which is committed by the Turks, from which the retailer alone suffers. It is also adulterated with the extract of poppy capsules, or of the whole plant; with that of chelidonium majus, with gum arabic or tragacanth, with the oil of linseed, and even with the dung of oxen.
OVUM. L. (Phasianus Gallus. Ovum.)
The Egg of the Domestic Fowl.
Vitellus, The Yolk or Yelk, is principally employed in pharmaceutical operations, for rendering oils and balsams miscible with water. It is gently laxative.