Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/857

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OPIUM 793 quality yielding from 8 to 13 per cent., while the variety met vith iu the form of sticks sometimes contains only 2 to 3 per cent. Indian opium is remarkable for the low percentage of morphia, the average yield being only 3 to 4 per cent., although samples of the kinds known as Khandesh and Garden Fatna have afforded on analysis 6 to 7 per cent. Chinese opium is similar in this respect, giving, as a rule, only 3 to 7 per cent, of this alkaloid. The amount of morphia present in opium bears no relation to the preference exhibited by smokers, opium containing a large quantity of morphia being generally considered by them as inferior in quality and apt to cause headache. For use in medicine those containing a large percentage of morphia are the most esteemed. Opium dried as soon as possible after being collected is usually much richer in morphia than that kept for some time in a moist state and exposed to the air ; and poppies grown on the hills yield an opium containing more morphia than those cultivated on the plains. Guibourt found that opium twenty years old contained less morphia than when previously analysed in the fresh state. To ascertain the percentage of morphia, the merchant extracts, by means of an instrument like a cheese-cutter, a small cylinder of opium about the thickness of a penholder and about 2 inches long, out of one-third of the pieces in a chest, and it is considered that the analysis of these pieces will fairly represent the value of the chest. Various methods are adopted for estimating the morphia, most of which depend upon the fact that this alkaloid can be precipitated from its salts by ammonia, and that it is insoluble in ether and only very slightly soluble in cold water. When pure it forms colourless shining prismatic crystals having an alkaline reaction. It unites with acids to form salts, most of which are soluble in water. It is soluble in 36 parts of boiling and 100 of cold alcohol, in 500 of boiling water, and very slightly in chloroform. It is also soluble in the fixed and volatile oils, and in solution of the fixed caustic alkalis and lime water, but only very slightly in caustic ammonia. With nitric acid it gives a red colour passing into yellow, with test solution of ferric chloride a blue colour which is destroyed by free acids or alcohol, and with sulphuric acid and bichromate of potash a greenish but not a purple or violet colour. Heated in the open air it burns readily, a portion being volatilized. The salts chiefly used in medicine arc the hydrochlorate, sulphate, and acetate ; and for subcutaneous in jection the tartrate has been recommended by Erskinc Stuart, since it is more soluble, and more concentrated solutions can be used of it than of the other salts. Heated in a sealed tube with hydrochloric acid, morphia is decomposed and an alkaloid named "apomorphia," C 17 H 17 N0 2 , formed, which is one of the most speedy and effectual emetics known, and is of great value in cases of accidental poisoning, the subcutaneous injection causing the emptying of the contents of the stomach in a few minutes even when all ordinary emetics fail to act. In minute doses it has also valuable expectorant properties. It is soluble in ether and 50 parts of alcohol and in 68 parts of boiling water, but the solution soon decomposes, and assumes a green colour ; consequently it should be made fresh for use in medicine. Codcia, C 18 H 21 N0 3 , exists in opium in combination with meconic acid, and remains in solution after the morphia is precipitated by ammonia ; it may be obtained by evaporating the solution and purifying the crystals that form by dissolving them in hot ether, from which it crystallizes out on cooling in rather large octahedral prisms. It differs from morphia in not being soluble in solution of caustic potash or soda, while with nitric acid (sp. gr. 1 200) it gives a yellow solution which does not become red. It is soluble in 17 parts of boiling and 80 of cold water. Codeia has been found also in Turkish, French, and Indian opiums. Narcotin, C 23 H 23 N0 7 . This substance exists chiefly in a free state in opium ; being insoluble in cold water, it is left behind in consider able quantity when opium is macerated in that liquid, although a small portion, probably in combination with sulphuric acid, is dis solved. It is, however, very soluble in ether and benzol, and may be readily obtained by means of these solvents from the crude drug. It is doubtful if it should be classed with the alkaloids, for, although it forms definite compounds with some of the mineral acids, it does not exert any influence on vegetable colours. It differs from morphia in being insoluble in the caustic alkalis and not producing a blue colour with ferric salts. When heated on a piece of paper over a candle it leaves a greasy stain. Narccia, G^.^R.^Q^, has been also used occasionally in medicine. Its alkaloidal character has been disputed ; but it is now generally classed as an alkaloid. It differs from morphia in giving a blue colour with dilute mineral acids, but does not give a blue colour with ferric salts or a red colour with nitric acid. For recent details concerning the less important alkaloids reference may be made to Dr Hesse s papers, translated in the Pharm. Journ. and Trans., September 1870, p. 205, and January 1872, p. 549. Opium of good quality for medicinal use should not lose more than 12^ per cent, of water in drying, should not yield more than 8 per cent, of ash from the dried drug, and ought to afford at least 60 per cent, of matter soluble in water. It should be of somewhat tenacious consistence, yellowish brown colour, strong narcotic odour, and bitter taste. The preparation of crude opium most largely used in medicine is the tincture, commonly known as "laudanum." It is composed of 1^ oz. of powdered opium and 1 pint of spirit of wine of specific gravity 920. This name was, however, at first applied to a solid preparation, a pill-mass made of opium and various aromatics, which in the London Pharmacopoeia of 1639 consisted of saffron, castor, ambergris, musk, and oil of nutmeg. The liquid preparation which bears the name of laudanum was apparently first introduced by the celebrated Dr Sydenham, and was inserted in the London Pharmacopoeia for 1721. It also contained aromatics. Physiological Action. See NARCOTICS, supra, pp. 231-2. Medicinal Uses. The chief value of opium is to relieve pain, to relax spasm, to allay both local and general irrita tion of the nervous system, and to procure sleep. Its power of diminishing secretions is taken advantage of in the cure of catarrh, bronchorrhoea, diarrhoea, and other forms of . inflammation of the mucous membranes accompanied with excessive secretion, and also in diabetes. It is found of great value when conjoined with emetics in improving or stimulating the secretions of the skin. Its use is dangerous in inflammation of the brain or determination of blood to the head. The action of opium is exerted much more powerfully in proportion upon infants than upon adults, as small a dose as one drop of laudanum having proved fatal to an infant. For remedies in cases of poisoning see POISONS. Morphia differs slightly in its properties from opium. It is less stimulant, and does not produce the full diaphoretic action ; it causes less headache, nausea, and constipation. When used hypodermically its action is more rapid and smaller doses are required. Codeia is used in diabetes, in coughs, &c. Narceia is considered to be purely hypnotic. Narcotin is official in the pharmacopoeia of India as a tonic in general debility arising from pro longed lactation, and in convalescence from acute febrile and inflammatory diseases. Opium- eating. Opium, like many other poisons, pro duces after a time a less effect if frequently administered as a medicine, so that the dose has to be constantly increased to produce the same result on those who take it habitu ally. When it is used to relieve pain or diarrhoea, if the dose be not taken at the usual time the symptoms of the disease recur with such violence that the remedy is speedily resorted to as the only means of relief, and thus the habit is exceedingly difficult to break off. Opium -eating is chiefly practised in Asia Minor, Persia, and India. Opinions differ widely as to the injurious effect of the habit ; the weight of evidence appears, however, to indicate that it is much more deleterious than opium-smoking. It has been practised in India from very ancient times ; some idea of its prevalence there may be gathered from the fact that the mere licence fees for one year amounted to 493,343, and that some of the opium dealers in Calcutta have each no less than seventeen shops where this drug only is sold. The following statistics collected by Tincent Richards regarding Balasor in Orissa throw some light on the influence of this practice on the health. He estimates that one in every 12 or 14 of the population use the drug, and that the habit is increasing. Of the 613 opium-eaters examined by him he found that the average age at which the habit was commenced was 20 to 26 years for men and 24 to 30 years for women. Of this number 143 had taken the drug for from 10 to 20 years, 62 for from 20 to 30 years, and 38 for more than 30 years. The majority took their opium twice daily, morning and evening, the quantity taken varying from 2 to 46 grains daily, large doses being the exception, and the average 5 to 7 grains daily. The dose, when large, had been increased from the beginning ; when small, there had usually been no increase at all. The causes which first led to the increase of the drug were disease, example, and a belief in its aphrodisiac powers. The diseases for which it was chiefly taken were malarial fever, dysentery, diarrhoea, spitting of blood, rheumatism, and elephantiasis. A number began to take it in the famine year, 1866, as it enabled them to exist on less iood and mitio-ated their sufferings ; others used it to enable them to undergo fatigue and to make long journeys. Mr Richards concludes that the excessive use of opium by the agricultural classes, who are the chief consumers in Orissa, is very rare indeed. Its moderate use may be and is indulged in for years without producing any decided or appreciable ill effect except weakening the reproductive powers, XVII. ioo