This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Scammony is the concrete milky juice of the root of Convolvulus Scammonia, a climbing perennial plant of Syria and Asia Minor, with a long tapering root, and numerous slender, twining stems. The dried root has been adopted as an officinal by the British Pharmacopoeia, rather, however, for the preparation of the resin of scammony, than for use itself as a medicine. in the collection of scammony, the root is cut off obliquely near the top, and the juice, as it exudes, received into small shells, whence it is transferred into some convenient receptacle, in which it is allowed to harden. in the course of concretion, it probably undergoes a slight fermentation, attended with the production of minute bubbles of air throughout its substance, which it retains when it becomes solid. Very little, however, of the pure concrete juice is sent into the market. it is almost always more or less mixed with foreign substances, as meal, chalk or other form of carbonate of lime, gummy matter, an extract prepared from the plant, etc. This admixture is made partly by the peasants who collect the scammony, partly after it lias been brought into the market of Smyrna; and, in the latter place, the adulteration is carried on according to a regulated plan, the amount of impurity being graduated inversely to the price. Formerly, the better kinds were sold under the name of Aleppo scammony, from the town in the vicinity of which the drug was collected; and the inferior kinds under that of Smyrna scammony, from the place of export; but this distinction has been abandoned, as it no longer applies to the drug existing in the markets; almost the whole that is used, the better as well as the worse, coming from Smyrna.
Properties Scammony is in two distinct forms, one of which, supposed to be tolerably pure, is called virgin scammony, the other, in which there is almost always more or less admixture of impurities, may be denominated common scammony.
Virgin scammony is in irregular lumps, grayish on the outside, easily broken, with a fracture somewhat shining, resinous, and of a greenish-black colour, or grayish-green becoming black on exposure, and translucent at the edges. Examined by a magnifying glass, it is seen to be full of minute air-cells.
Common scammony is in circular cakes, flat on both sides, or planoconvex, from four to six inches in diameter, and from half an inch to two inches thick, of different colour in different specimens, some being of a light greenish-gray, others ash, or olive, or slate-coloured, and sometimes almost black. This variety is compact, heavy, hard, finely porous, with a fracture generally more or less shining, though sometimes dull, of a grayish colour, becoming darker on exposure, and with translucent splinters.
Both kinds yield a light-gray powder. The smell is feeble, but somewhat like that of old cheese; the taste, very slight at first, is after a time acrid, and sometimes slightly bitterish.
Scammony is essentially a gum-resin, with some other unimportant ingredients. it yields the gum to water, the resin to alcohol or ether, and both to diluted alcohol. Rubbed up with water, it forms a milky emulsion. The activity of the medicine resides exclusively in the resin, the proportion of which differs very much in the different specimens; amounting to 90 per cent. in the purest scammony; but, in that to be found in the market, varying from 80 down to about 40 per cent., and, in the greatly adulterated specimens, sinking to 10 per cent. or lower. The proportion of resin may be considered as a test of the strength and purity of the drug. The adulteration with meal may be detected by the blue colour imparted by the starch to iodine; that with carbonate of lime, by effervescence with muriatic acid.
Substances have been sold as scammony which were derived from other plants, or entirely factitious, being made up of materials not existing in the genuine drug. One of these, often designated as Montpel-lier Scammony, is said to be prepared, in the South of France, from the juice of Cynanchum monspeliacum. They are now, probably, not to be found in our shops.
Scammony has been employed from the earliest records of medicine. it is an energetic, hydragogue cathartic, generally producing more or less griping when it operates, sometimes acting harshly, and, in over-doses, capable of producing dangerous inflammation of the gastro-intestinal mucous membrane. it is probable that the gum qualifies the harshness of the resinous ingredient, by involving its particles, and thus mechanically preventing their full effect on the surface of the membrane; and some of the additions made to it, in its place of production, viewed in the same light, though they render a larger dose of the medicine necessary, may prove serviceable by moderating its violence. Scammony is seldom administered alone, but generally with other cathartics, to give them increased energy or rapidity of action. it is occasionally combined with calomel; but is probably most used as an ingredient of the compound extract of colocynth, and consequently of the compound cathartic pills, of which that extract forms a part. it may be employed whenever an energetic purgative is required, and there is no irritability of stomach, or gastric or intestinal inflammation. its griping may be obviated, in some degree, by giving aromatics at the same time.
The dose of virgin scammony is from 5 to 15 grains, that of the common kind, from 10 to 30 grains. The medicine is best administered in emulsion, made by rubbing it up with gum arabic or almonds, sugar, and one of the aromatic waters. There are several officinal preparations.
Compound Powder of Scammony (Pulvis Scammonii Compositus, Br.) consists of four parts of scammony, three of jalap, and one part of ginger, separately finely powdered, then thoroughly mixed, and lastly passed through a fine sieve. Such combinations are, I think, best left to extemporaneous prescription. The dose of the powder is from ten to thirty grains.
Confection of Scammony (Confectio Scammonii, Br.) is a British preparation, made by rubbing powdered scammony and ginger with syrup and honey into a uniform mass, and mixing with this a small proportion of the oils of caraway and cloves. The dose is from thirty grains to a drachm.
Resin of Scammony (Resina Scammonii, U. S.; Scammonia Resina, Br.) is directed, by the U. S. Pharmacopoeia, to be made by exhausting scammony with alcohol, concentrating the tincture to a syrupy consistence, and pouring the residue into water. The precipitate which forms is then separated, thoroughly washed with water, and dried with a gentle heat. The British Pharmacopoeia prepares it from the powdered root of the Convolvulus scammonia, by first exhausting it with alcohol, then adding water to the tincture to precipitate the resin, distilling off the alcohol, allowing the residue to stand till cool, then pouring off the water, washing the precipitate thoroughly with boiling water, and drying it. The resin is nearly identical in effects as prepared by the two processes, being the active principle separated from the inert matter whether of the scammony or the root. The U. S. resin is of a greenish-brown colour, with a slight odour and taste of scammony, and is very soluble in ether and alcohol. if treated with charcoal, it becomes of a pale brownish-yellow, and loses the smell and taste of scammony. The British preparation is brownish, transparent, and of a sweetish fragrant odour, which is wholly different from that of scammony, and is derived from the root. The dose is from four to eight grains. The best form for exhibition is an emulsion made by rubbing it with unskimmed milk, in which any taste that it may have is quite lost.