(2.) Another colouring-matter, dissolving in concentrated sulphuric acid with the production of a fine blue violet colour, the discoverer has named Scleroidin. This is not soluble in alcohol, ether, chloroform, or water, but dissolves in alkaline solutions, potash producing a splendid violet colour; yield about 1 per 1000.
(3, 4.) Two crystalline substances, which may be obtained from ergot powder, first treated with an aqueous solution of tartaric acid, and the colouring-matters extracted by ether. One Dragendorff names Sclerocrystallin (C10H10O4); it is in colourless needles, insoluble in alcohol and water, with difficulty soluble in ether, but dissolving in ammonia and potash solutions. The other crystalline substance is thought to be merely a hydrated compound of sclerocrystallin. Both are without physiological action.
Kobert recognises two active substances in ergot, and two alone; the one he calls sphacelic acid, the other cornutin.
§ 579. Detection of Ergot in Flour (see “Foods”).—The best process is to exhaust the flour with boiling alcohol. The alcoholic solution is acidified with dilute sulphuric acid, and the coloured liquid examined by the spectroscope in thicker or thinner layers, according to the depth of colour. A similar alcoholic solution of ergot should be made, and the spectrum compared. If the flour is ergotised, the solution will be more or less red, and show two absorption bands, one in the green, and a broader and stronger one in the blue. On mixing the original solution with twice its volume of water, and shaking successive portions of this liquid with ether, amyl alcohol, benzene, and chloroform, the red colour, if derived from ergot, will impart its colour to each and all of these solvents.
§ 580. Pharmaceutical Preparations.—Ergot itself is officinal in all the pharmacopœias, and occurs in grains from 1⁄3 to 1 inch in length, and about the same breadth, triangular, curved, obtuse at the ends, of a purple colour, covered with a bloom, and brittle, exhibiting a pinkish interior, and the microscopical appearances already detailed. Ergot may also occur as a brown powder, possessing the unmistakable odour of the drug. A liquid extract of the B.P. is prepared by digesting 16 parts of ergot in 80 parts of water for twelve hours, the infusion is decanted or filtered off, and the digestion repeated with 40 parts of water; this is also filtered off, and the residue pressed, and the whole filtrate united and evaporated down to 11 parts; when cold, 6 parts of rectified spirit are added, and, after standing, the liquid is filtered and made up to measure 16. A tincture and an infusion are also officinal; the latter is very frequently used, but seldom sold, for it is preferable to prepare it on the spot. The tincture experience has shown to be far inferior in power to the extract, and it is not much used. Ergotin is a purified extract of uncertain strength; it is used for hypodermic injection; it should be about five times more active than the liquid extract.
§ 581. Dose.—The main difficulties in the statement of the medicinal dose, and of the minimum quantity which will destroy life, are the extreme variability of different samples of ergot, and its readiness to decompose. A full medicinal dose of ergot itself, as given to a woman in labour, is 4 grms. (61·7 grains), repeated every half hour. In this way enormous doses may be given in some cases without much effect. On the other hand, single doses of from 1 to 4 grms. have caused serious poisonous symptoms. The extract and the tincture are seldom given in larger doses than that of a drachm as a first dose, to excite uterine contraction. In fact, the medical practitioner has in many cases to experiment on his patient with the drug, in order to discover, not only the individual susceptibility, but the activity of the particular preparation used. From the experiments of Nikitin, it is probable that the least fatal dose of sclerotic acid for an adult man is 20 mgrms. per kilogrm.
§ 582. Ergotism.—Ergotised cereals have played a great part in various epidemics, probably from very early times, but the only accurate records respecting them date from the sixteenth century. According to Dr. Tissot,[603] the first recorded epidemic was in 1596, when a strange, spasmodic, convulsive disease broke out in Hessia and the neighbouring regions. It was probably due to spurred rye. In Voigtländer, the same disease appeared in 1648, 1649, and 1675; in 1702 the whole of Freiberg was attacked. In Germany and in France successive epidemics are described throughout the eighteenth century. In France, in 1710, Ch. Noel, physician at the Hôtel Dieu, had no less than fifty cases under treatment at the same time.
[603] Dr. Tissot in Phil. Trans., vol. lv. p. 106, 1765. This is a Latin letter by Dr. Baker, and gives a good history of the various epidemics of ergotism.