542 PREPARATION OF SNUFF. nicotylia and some fatty matters, and rises with them to the surface when the mixture is left at rest. In order to purify the alkali, powdered oxalic acid is added by degrees to the decanted ethereal solution. The oxalate of nicotylia, being insoluble in ether, forms a dense syrupy layer at the bottom of the vessel. It is washed two or three times with pure ether; and the nicotylia is separated by the addition of a fresh quantity of solution of potash and ether. The ethereal solution is decanted into a retort, provided with the means of transmitting a current of dry hydrogen through it; the ether is then driven off, and the residue exposed for twenty-four hours to a temperature of 284°, in order to expel the last traces of ammonia and ether; after which the temperature is raised to 356° (180° C.), when the nicotylia distils over in a state of purity. (1391) Preparation of Snuff.-A full account of this operation, as performed at the Imperial tobacco works in Paris, is given by Pelouze and Fremy (Traité de Chimie, 2nd ed., iv. 437). The following is an outline of the steps of the manufacture :The stronger kinds of tobacco are those which are preferred for the preparation of snuff. The leaves are spread out in thin layers upon a stone pavement, and moistened with about a fifth of their weight of a solution of chloride of sodium in water (sp. gr. 1089). The moistened leaves are next cut into blocks, and are then piled up in large rectangular heaps, in quantities of 40 or 50 tons. These masses gradually enter into fermentation, and the temperature rises sometimes as high as 170°, but usually it does not exceed 140° (60° C.). If the temperature be allowed to rise too high, some parts of the mass become black, as though they had been charred. Spring and autumn are the seasons most favourable for the commencement of this operation, which requires careful watching to prevent the development of heat from becoming excessive. In about five or six months the temperature becomes stationary, or begins to decline; the heaps are then opened out, and the fermented mass is submitted to grinding. The pale brown and comparatively dry powder thus obtained is next mixed with about four-tenths of its weight of the solution of chloride of sodium, and is passed through a sieve, to ensure a uniform moistening of the mass; after which it is packed in large oaken chests, capable of containing from 25 to 50 tons of the material. Here the snuff remains for nine or ten months, and undergoes a second fermentation, in the course of which the temperature in the centre of the mass rises to 120° or 130°. During this process the snuff acquires its well-known dark colour, PREPARATION OF SNuff. 543 and the aroma is developed. The mass is, however, still far from uniform in quality throughout; it is therefore transferred to a second chest, in which operation all the different parts of the heap are thoroughly mixed together; after the lapse of two months, it is a second time turned over, and, sometimes, a third transfer is deemed requisite. When considered ripe, the contents of the various chests are mixed in a large room capable of containing 350 tons of snuff. Here it is left for about six weeks, to render the entire mass uniform in quality; and finally it is sifted into barrels for the market. The whole process of manufacture thus occupies from eighteen to twenty months. During the fermentation, about two-thirds of the nicotylia is destroyed. A small portion of this base appears to exist in snuff, in the uncombined form; but the greater part of the portion still remaining is left in the form of acetate, a certain amount of acetic acid having become developed during the fermentation. A portion of the decomposed nicotylia undergoes conversion into carbonate of ammonium, which is partially retained by the snuff; and the gradual volatilization of this salt appears to favour the conversion of nicotylia into vapour, and thus to occasion the pungent odour for which snuff is valued. The proportion of citric and malic acids becomes diminished during the fermentation; so that ordinary snuff has an alkaline reaction. A certain quantity of a peculiar essential oil appears also to be developed during the operation; and to the variable proportion of this oil, much of the difference in the flavour of the several varieties of snuff is owing. The quantity of potassic nitrate which fresh tobacco contains, passes over, unaltered, into the snuff. It may be remarked, that tobacco is one of the most exhausting crops which can be grown upon any soil, since it carries off an enormous amount of mineral constituents (the proportion of ash amounting to not less than 21 per cent. of the dry leaf). Among these constituents, nitric acid is found in quantity often exceeding 2 per cent. of the dry leaf; whilst the salts of potassium amount to more than a third of the saline residue. It is probable that the active principle of henbane, or Hyoscyamus niger, is a volatile base, analogous to nicotylia; since a portion of some volatile base comes over when the plant is distilled with a solution of potash. Much of the alkaloid, however, is decomposed in this operation: its composition has not been determined. 544 ALKALOIDS OF THE CINCHONAS. 2. Bases which contain Oxygen. (a) Alkaloids of the Cinchonas. (1392) In the bark of the different varieties of Cinchona, several well-characterized and important bases occur. They are all closely related to each other in composition, and are found chiefly in the bark in combination with quinic and quinotannic acids. The most abundant of these bodies are cinchonia and quinia, each of which is accompanied by, or is convertible into, two isomeric bases, termed respectively, cinchonidine and cinchonicine, quinidine and quinicine. Besides these, a base termed aricine, or cinchovatine, has been found in the bark of Cinchona ovata. Both cinchonia and quinia form two classes of salts; one class of which has been regarded, until quite recently, as being basic, whilst the other was supposed to be normal: the common medicinal sulphate of quinia, for example, was viewed as the basic sulphate. Strecker has, however, shown that the formula of the base must be doubled, in which case this salt will be normal, whilst that formerly regarded as normal must be an acid salt. The salts which these bases form with the smaller proportion of acid are very sparingly soluble in water, but are readily dissolved on the addition of any free acid. 20 241 Quinia and cinchonia, as well as cinchonidine, appear to belong to Hofmann's class of nitrile bases; since, when treated with iodide of methyl, or of ethyl, they yield bases of the ammonium type. Hydrated ethyloquinium oxide [(Є„H2N ̧Ð1⁄2), Є,H,HO] is a powerful base, which attracts carbonic acid from the air the methyloquinium iodide consists of (20H24N2→2)ЄH ̧I. The iodide of the corresponding methylic derivatives of the metameric cinchonia and cinchonidine consists of (Є2H2N ̧Ð)ЄH ̧I. Induced by these and other circumstances, Strecker doubles the old formula of these alkaloids, representing quinia as €20H4N,2. 20 Cinchonia and quinia, with their isomerides, are decomposed when distilled with caustic potash. Several volatile bases are formed, amongst which quinoline (1372) is the most abundant; and potassic formiate is left in the retort. Cinchonia, and its isomeric congeners, are most abundant in the pale Peruvian bark, Cinchona condaminea. Quinia, and its isomeric companions, occur most abundantly in the yellow bark, or C. calisaya; whilst the red bark, C. succirubra, contains both classes of alkaloids. Quinia, from its febrifuge and antiperiodic powers, is the most highly esteemed of these alkaloids for medicinal purposes; CINCHONIA-CINCHONIDINE. 545 though it appears that quinidine possesses similar therapeutic virtues to a nearly equal extent. 20 24 (1393) I. CINCHONIA [EHN20=308; Fusing pt. 329° (165° C.)]. crystallizes in large quadrilateral prisms, which are anhydrous; it is less soluble in alcohol than quinia, and is insoluble in ether. Cinchonia is dissolved by solutions of the alkalies and alkaline bicarbonates. At 329° it fuses to a colourless liquid, which becomes a crystalline mass on cooling; when heated further it is partially volatilized; but a portion at the same time undergoes decomposition. It may be sublimed readily in an atmosphere of hydrogen. Its salts are intensely bitter; they are precipitated by infusion of galls, as well as by solutions of the oxalates, tartrates, and gallates. Two atoms of the hydrogen in cinchonia admit of displacement by chlorine, and by bromine : the new compounds thus obtained retain basic powers. 201 24 2 2 201 24 2 Cinchonia Sulphate [(EHN,O),H2SO4, 2 H ̧Ð=714+36] crystallizes in irregular prisms, which melt, like wax, at a little beyond 212°; when gently heated it emits a phosphorescent light. If it be first moistened with water acidulated with sulphuric acid, it may be kept in a fused condition for some hours; during which time it gradually passes into sulphate of cinchonicine (Pasteur). If heated more strongly it is converted into a resinous mass of a beautiful red colour. The acid sulphate (H,CH,NO, ᎦᎾ 43 H2O) is very soluble both in water and in alcohol; it crystallizes from a hot solution, in large, well-defined, rhombic octohedra. When cinchonia is dissolved in sulphuric acid, and heated with peroxide of lead, it produces a red-coloured compound; when mixed with chlorine water and afterwards with ammonia, no green tint is produced, as occurs when quinia is similarly treated. Its salts are generally more soluble both in alcohol and in water than those of quinia. 2. Cinchonidine (Є20H24N,O); Fusing pt. 347° (175° C.).—This alkali, which is isomeric with cinchonia, occurs naturally in certain varieties of cinchona bark; and may be obtained by the spontaneous evaporation of its alcoholic solution, in hard, brilliant, striated, rhomboidal prisms, which are anhydrous, and insoluble in ether. Its solution in absolute alcohol produces left-handed rotation upon a polarized ray; whilst cinchonia produces rotation to the right. Cinchonidine fuses at 347°, and at a higher temperature is decomposed, emitting an odour of oil of bitter almonds. When the solutions of the salts of this base are mixed with the caustic alkalies, or with the carbonates or bicarbonates of 546 CINCHONIDINE-CINCHONICINE-QUINIA. these bases, they give a white precipitate of cinchonidine, which gradually becomes crystalline. Hydrodisodic phosphate, corrosive sublimate, nitrate of silver, and ammonium sulphocyanide, also give white precipitates in solutions of salts of cinchonidine. At a high temperature, the salts of cinchonidine pass into those of cinchonicine. The Sulphate [(20H,N,O), H2SO,] crystallizes in. stellate groups of silky needles, the solution of which is neutral to test papers. The hydrochlorate crystallizes in large, brilliant, rhomboidal prisms, soluble in about twenty-seven parts of water. 3. Cinchonicine is a third base, which has the same composition as the two foregoing ones. It is precipitated from its salts in the form of a resinous mass, which is freely soluble in alcohol. This solution causes right-handed rotation of a ray of polarized light. Cinchonicine is best prepared by the action of heat upon cinchonia sulphate, in the manner already mentioned. 24 (1394) 4. QUINIA (€20H2N, 2, 3 H2O=324+54) is most abundant in the yellow bark (Cinchona calisaya), in which it occurs mixed with cinchonia, and combined with quinic and quinotannic acids. The quantity of the alkaloids varies in different specimens of bark, but the two together generally amount to 3.5 or 4 per cent. In order to extract the bases, the pulverized bark is boiled with 8 or 10 times its weight of water acidulated with 1 per cent. of oil of vitriol, or with 2 per cent. of hydrochloric acid. The liquid is strained through a cloth, and the residue is boiled twice with acidulated water. When the strained liquors are cold, milk of lime, or sodic carbonate, is added in slight excess; the precipitate is submitted to pressure, and then treated with hot alcohol. If the proportion of cinchonia be considerable, it crystallizes as the liquid cools; and a fresh quantity is obtained by distilling off one-half of the alcohol from the residue, whilst the quinia remains in solution: the liquid is then neutralized with sulphuric acid. The separation of the two bases is afterwards completed by crystallizing the mixed sulphates from a slightly acid solution; the sulphate of quinia being much the less soluble of the two, crystallizes first. The alkaloid is then thrown down from the sulphate by adding ammonia. Cinchonia and cinchonidine may also be separated from quinia by means of ether, which dissolves the quinia, and leaves the cinchonia and cinchonidine. Quinia may be obtained in crystals, though with some difficulty, by allowing its alcoholic solution to evaporate spontaneously in a cool place: silky needles are thus formed; they are dissolved much more readily by cold alcohol than the crystals of cinchonia. Quinia requires about 350 parts of water for its |