curarine produces the same reaction with sulphuric acid and chromate of potassa as strychnia. They differ however in this, that curarine is colored red by sulphuric acid alone, and it gives much more permanent colorations with chromate of potassa than strychnine (DRAGENDORFF). 9. Strong chlorine water produces in solutions of strychnia salts a white precipitate, soluble in ammonia to a colorless fluid.

10. Strong nitric acid dissolves strychnia and its salts to a colorless fluid, which turns yellow when heated.

11. Tannic acid produces in solutions of strychnia salts heavy white precipitates, insoluble in hydrochloric acid.

+

It

1. Brucia occurs with strychnia (see § 238). Crystallized brucia (Br+8 aq.) appears either in the form of transparent straight rhombic prisms, or in that of crystalline needles aggregated into stars, or as a white powder composed of minute crystalline scales. Brucia is difficultly soluble in cold, but somewhat more readily in hot water. dissolves freely in alcohol, both in absolute and dilute, also in cold, but more readily still in hot, amylic alcohol; but it is almost insoluble in ether. Its taste is intensely bitter. When heated, it fuses with loss of its water of crystallization. By cautious heating it may be sublimed unchanged (see foot-note § 233, 1).

2. Brucia neutralizes acids completely. The salts of brucia are readily soluble in water, and of an intensely bitter taste. Most of them are crystallizable.

3. Potassa and carbonate of soda throw down from solutions of salts of brucia a white precipitate of brucia, insoluble in an excess of the precipitant. Viewed under the microscope, immediately after precipitation it appears to consist of very minute grains; but upon further inspection, these grains are seen-with absorption of water-to suddenly form into needles, which latter subsequently arrange themselves without exception into concentric groups. These successive changes of the precipitate may be traced distinctly even with the naked eye.

4. Ammonia produces in solutions of salts of brucia a whitish precipitate, which appears at first like a number of minute drops of oil, but changes subsequently-with absorption of water-to small needles. The precipitate redissolves, immediately after separation, very readily in an excess of the precipitant; but after a very short time-or, in dilute solutions, after a more considerable lapse of time-the brucia, combined with crystallization water, crystallizes from the ammoniacal fluid in small concentrically grouped needles, which addition of ammonia fails to redissolve.

5. Bicarbonate of soda produces in neutral solutions of salts of brucia a precipitate of brucia, combined with crystallization water; this precipitate separates after the lapse of a short time, in form of concentrically aggregated needles of silky lustre, which are insoluble in an excess of the precipitant, but dissolve in free carbonic acid (compare Strychnia). Bicarbonate of soda fails to precipitate acid solutions of salts of brucia; and it is only after the lapse of a considerable time, and with the escape.

of the carbonic acid, that the alkaloid separates from the fluid in regular and comparatively large crystals.

6. Concentrated nitric acid dissolves brucia and its salts to intensely red fluids, which subsequently acquire a yellowish-red tint, and turn yellow upon application of heat. Upon addition of protochloride of tin or sulphide of ammonium to the heated fluid, no matter whether concentrated or after dilution with water, the faint yellow color changes to a most intense violet.

7. If a little brucia is treated with from 4 to 6 drops of pure concen→ trated sulphuric acid, a solution of a faint rose color is obtained, which afterwards turns yellow. If 10 or 20 drops of sulphuric acid mixed with some nitric acid (foot-note § 233, 7) are added, the fluid transiently acquires a red, afterwards a yellow color. Addition of binoxide of manganese transiently imparts a red, then a gamboge tint to the fluid. If the fluid is then, with proper cooling, diluted with 4 parts of water, and ammonia added to nearly neutral reaction, or even to alkaline reaction, the solution acquires a gold-yellow color (J. ERDMANN).

8. Addition of chlorine water to the solution of a salt of brucia imparts to the fluid a fine bright red tint; if ammonia is then added, the red color changes to yellowish-brown.

9. Sulphocyanide of potassium produces in concentrated solutions o salts of brucia immediately, in dilute solutions after some time, a granular crystalline precipitate, which, under the microscope, appears composed of variously aggregated polyhedral crystalline grains. Friction applied to the sides of the vessel promotes the separation of the precipitate.

10. Chloride of mercury also produces a white granular precipitate, which, under the microscope, appears composed of small roundish crystalline grains.

11. Tannic acid produces in solutions of salts of brucia, heavy dirty white precipitates, soluble in acetic acid, insoluble in hydrochloric acid.

c. VERATRIA, or VERATRINE (C, H, N, O,,) Ve.

§ 240.

52 2

1. Veratria occurs in various species of veratrum, especially in the seeds of veratrum sabadilla (with veratric acid), and in the root of veratrum album (with jervine). It appears in the form of small prismatic crystals which acquire a porcelain-like look in the air, or as a white powder of acrid and burning, but not bitter taste. It is exceedingly poisonous. Veratria acts with great energy upon the membranes of the nose; even the most minute quantity of the powder excites the most violent sneezing. It is insoluble in water; in alcohol it dissolves readily, but more sparingly in ether. At 150° it fuses like wax, and solidifies upon cooling to a transparent yellow mass. By cautious heating it may be sublimed unchanged (see foot-note § 233, 1).

2. Veratria neutralizes acids completely. Some salts of veratria are crystallizable, others dry up to a gummy mass. They are soluble in water, and have an acrid and burning taste.

3. Potassa, ammonia, and the monocarbonates of the alkalies produce in solutions of salts of veratria a flocculent white precipitate, which, viewed under the microscope immediately after precipitation, does not appear crystalline. After the lapse of a few minutes, however, it alters its

appearance, and small scattered clusters of short prismatic crystals are observed, instead of the original coagulated flakes. The precipitate does not redissolve in an excess of potassa or of carbonate of potassa. It is slightly soluble in ammonia in the cold, but the dissolved portion separates again upon application of heat.

4. With bicarbonate of soda and bicarbonate of potassa the salts of veratria comport themselves like those of strychnia and brucia. However, the veratria separates readily upon boiling, even from dilute solutions.

5. If veratria is acted upon by concentrated nitric acid, it agglutinates into small resinous lamps, which afterwards dissolve slowly in the acid. If the veratria is pure, the solution is colorless.

6. If veratria is treated with concentrated sulphuric acid, it also agglutinates at first into small resinous lumps; but these dissolve with great readiness to a faint yellow fluid, the color of which gradually increases in depth and intensity, and changes afterwards to a reddishyellow, then to an intense blood-red, and finally to purple red. The color persists 2 or 3 hours, then disappears gradually. Addition of sulphuric acid, containing nitric acid, or of binoxide of manganese causes no great change of color. If the fluid is then diluted with water, and ammonia added until the reaction is nearly neutral, a yellowish solution is obtained, in which ammonia added in excess produces a greenish light-brown precipitate (J. ERDMANN).

7. If veratria is dissolved in strong hydrochloric acid, a colorless fluid is obtained, which by long boiling acquires an intensely red tint, permanent on standing. The reaction is very delicate, and occurs not only with the perfectly pure veratrine but with the ordinary commercial alkaloid (TRAPP).

8. Sulphocyanide of potassium produces only in concentrated solutions of salts of veratria flocculent, gelatinous precipitates.

9. Addition of chlorine water to the solution of a salt of veratria imparts to the fluid a yellowish tint, which upon addition of ammonia, changes to a faint brownish color. In concentrated solutions chlorine produces a white precipitate.

d. ATROPIA, or ATROPINE (C,, H„NO).

§ 241.

1. Atropia occurs in all parts of the deadly nightshade (atropa belladonna), and of the thorn-apple (datura stramonium). It forms small brilliant prisms and needles. It is, when pure, without odor and nauseously bitter; it fuses at 90°, and volatilizes at 140° with partial decomposition. By heating between watch-glasses it volatilizes without blackening. The sublimate is soft and oily. Atropia dissolves in about 300 parts of cold water, and 60 parts of boiling water, it is very soluble in alcohol, the saturated alcoholic solution is precipitated by the addition of a small quantity of water. It is very soluble in chloroform and amylic alcohol, but it requires about forty parts of ether for solution. 2. Atropia combines with acids, forming salts, some of which, particularly the acid salts, do not crystallize. The salts dissolve easily in water and alcohol, scarcely at all in ether. The aqueous solutions of the salts acquire a dark color by long heating.

3. Atropia and its salts are active narcotic poisons. When applied to the eye they dilate the pupil for a considerable time. Hyoscyamine has the same action; but the dilatation in this case is rather slower in making its appearance and more lasting.

4. Potassu and monocarbonates of the fixed alkalies added to concentrated aqueous solutions of salts of atropia precipitate a portion of the alkaloid. The precipitate, which is at first pulverulent, does not dissolve in excess of the precipitant more readily than in water. By long standing it becomes crystalline. Ammonia likewise produces a precipitate, soluble in excess. Atropia is decomposed, in contact with fixed alkalies or with baryta water, slowly in the cold, rapidly on heating.

5. Carbonate of ammonia and bicarbonates of the alkalies do not precipitate solutions of salts of atropia.

6. Terchloride of gold added to aqueous solutions of salts of atropia throws down a compound of hydrochlorate of atropia and terchloride of gold in the form of a yellow precipitate which gradually turns crystalline.

7. Tannic acid produces in aqueous solutions of salts of atropia a white curdy precipitate soluble in ammonia.

8. If atropia is warmed with concentrated sulphuric acid to slight browning, and a few drops of water are added to the watch-glass, an agreeable odor is evolved, recalling the sloe blossom, or perhaps more the cheese rennet (galium verum). On further heating the odor in

creases.

9. Cyanogen gas passed into a sufficiently concentrated alcoholic solution of atropia produces a reddish-brown color (HINTERBERGER).

10. Picric acid does not precipitate solutions of pure salts of atropia. Consequently solutions of atropia which after acidification with dilute sulphuric acid give a precipitate with this reagent, must be considered to contain some other unknown alkaloid (HAGER).

Recapitulation and Remarks.

§ 242.

Strychnia may be separated from brucia, veratria, and atropia by means of absolute alcohol, since it is insoluble in that menstruum, whilst the latter alkaloids readily dissolve it. The identity of strychnia is best established by the reaction with sulphuric acid and the above-mentioned oxidizing agents; also by the form of its crystals-when thrown down by alkalies-viewed under the microscope; and lastly, by the form of the precipitates produced by sulphocyanide of potassium and chloride of mercury. Brucia and veratria may be separated from atropia by shaking the alkaline solution with petroleum ether (DRAGENDORFF). The latter takes up the brucia and veratria, but not the atropia. By separating the aqueous fluid from the petroleum ether and shaking it with ether the atropia may be obtained in ethereal solution. Brucia and veratria are not readily separated from one another, but may

*The only substance which besides curarine (see above), shows somewhat analogous reactions in this respect, is aniline. A. GUY has, however, called attention to the fact that aniline, treated with sulphuric acid and oxidizing agents, acquires a pale green color at first, which gradually deepens, and only then changes to a magnificent blue, which, after persisting some time, turns finally black.

be detected in presence of each other. The identity of brucia is best established by the reactions with nitric acid and protochioride of tin or sulphide of ammonium, or by the form of the crystalline precipitate which ammonia produces in solutions of salts of brucia. Veratria is sufficiently distinguished from brucia and the other alkaloids which we have treated of, by its characteristic deportment at a gentle heat, and also by the form of the precipitate which alkalies produce in solutions of its salts. To distinguish veratria in presence of brucia, the reaction with concentrated sulphuric acid or with hydrochloric acid is selected.

C. PROPERTIES AND REACTIONS OF CERTAIN NON-NITROGENOUS BODIES, ALLIED TO THE ALKALOIDS, VIZ., SALICINE, DIGITALINE, AND PICROTOXINE.

§ 243.

a. SALICINE (C20 H18 011).

1. Salicine exists in the bark and leaves of most kinds of willow and some kinds of poplar. It appears either in the form of white crystalline needles and scales of silky lustre, or, where the crystals are very small, as a powder of silky lustre. It has a bitter taste, is readily soluble in water and alcohol, but insoluble in ether.

2. No reagent precipitates salicine as such.

3. If salicine is treated with concentrated sulphuric acid, it agglutinates into a resinous lump, and acquires an intensely blood-red color, without dissolving; the color of the sulphuric acid is at first unaltered.

4. If an aqueous solution of salicine is mixed with hydrochloric acid and boiled for a short time, it suddenly becomes turbid with formation of sugar and deposits a white agglutinating precipitate (salire tine). If the precipitated liquor is now mixed with 1 or 2 drops of chromate of potassa and boiled, the saliretine will acquire a bright rose color, the characteristic odor of salicyligenic acid being emitted at the same time.

1. Digitaline exists in the leaves, seeds, and capsules of the foxglove (digitalis purpurea). It is usually white, amorphous, but it may also be obtained in crystals.* It is without odor, bitter, and an active poison, its powder irritates the eyes and causes sneezing. At 180° it becomes colored but does not fuse, above 200° it is completely decomposed.

2. Digitaline is neutral. It dissolves in all proportions in chloroform, and in about 12 parts of alcohol of 90° at the ordinary temperature, but more readily on boiling; it is less soluble in absolute alcohol. It is only very slightly soluble in ether free from alcohol. It is very difficultly soluble in water, even when boiling (1 part requires 1000 parts of boiling water), the solution, however, has a very bitter taste.

* NATIVELLE gives a method for preparing crystallized digitaline, see Journ. de Pharm. 9, 255-Zeitschr. f. Chem. 5, 401-Chem. Centr. Bl. 1870, 30. The commercial digitaline is frequently a mixture of various bodies, and this explains why the properties of digitaline as given by different chemists are found to vary so greatly.