+

into the soution, Mo+ 2 aq. separates,-especially after previous ebullition in the form of a crystalline powder. A more minute inspection, particularly through a magnifying-glass, shows this powder to consist of small acicular crystals; seen through a glass which magnifies 100 times, these crystals present the form of four-sided prisms.

5. Bicarbonate of soda and bicarbonate of potassa speedily produce in solutions of neutral salts of morphia a precipitate of hydrated morphia, in the form of a crystalline powder. The precipitate is insoluble in an excess of the precipitants. These reagents fail to precipitate acidified solutions of salts of morphia in the cold.

6. The action of strong nitric acid upon morphia or one of its salts, in the solid state or in concentrated solutions, produces a fluid varying from red to yellowish-red. Dilute solutions do not change their color upon addition of nitric acid in the cold, but upon heating they acquire a yellow tint.

7. Neutral sesquichloride of iron imparts to neutral solutions of salts of morphia a beautiful dark blue color, which disappears upon the addition of an acid. If the solution contains an admixture of animal or vegetable extractive matters, or of acetates, the color will appear clouded

and less distinct.

8. If iodic acid is added to a solution of morphia or of a salt of morphia, IODINE separates. In concentrated aqueous solutions the separated iodine appears as a kermes-brown precipitate, whilst to alcoholic and dilute aqueous solutions it imparts a brown or yellowish-brown color. The addition of starch-paste to the fluid, no matter whether made before or after that of the iodic acid, considerably heightens the delicacy of the reaction, since the blue tint of the iodide of starch remains still perceptible in exceedingly dilute solutions, which is not the case with the brown color imparted by iodine. As other nitrogenous bodies (albumen, caseine, fibrine, &c.) likewise reduce iodic acid, this reaction has only a relative value.

SECOND GROUP.

NON-VOLATILE ALKALOIDS WHICH ARE PRECIPITATED BY POTASSA FROM THE SOLUTIONS OF THEIR SALTS, BUT DO NOT REDISSOLVE TO A PERCEPTIBLE EXTENT IN AN EXCESS OF THE PRECIPITANT, AND ARE PRECIPITATED BY BICARBONATE OF SODA EVEN FROM ACID SOLUTIONS, if the latter are not diluted in a larger proportion than 1:100; Narcotina, Quina, Cinchonia.

+

a. NARCOTINA, or NARCOTINE (CH, NO, Na).

+

46

§ 231.

25

14

=

1. Crystallized narcotina (Na + aq.) appears usually in the form of colorless, brilliant, straight rhombic prisms, or, when precipitated by alkalies, as a white, loose, crystalline powder. It is insoluble in water. Alcohol and ether dissolve it sparingly in the cold, but somewhat more readily upon heating. Solid narcotina is tasteless, but the alcoholic and ethereal solutions are intensely bitter. Narcotina does not alter vegetable colors. At 338° F. it fuses, with loss of 1 eq. of water.

2. Narcotina dissolves readily in acids, combining with them to salts.

These salts have invariably an acid reaction. Those with weak acids are decomposed by a large amount of water, and, if the acid is volatile, even upon simple evaporation. Most of the salts of narcotina are amorphous, and soluble in water, alcohol, and ether; they have a bitter taste.

3. Pure alkalies, and alkaline carbonates and bicarbonates, immediately

+

precipitate from the solutions of salts of narcotine (Na + aq.) in the form of a white powder, which, seen through a lens magnifying 100 times, appears an aggregate of small crystalline needles. The precipitate is insoluble in an excess of the precipitants. If a solution of narcotina is mixed with ammonia, and ether added in sufficient quantity, the narcotina which has separated upon the addition of the ammonia, redissolves in the ether, and the clear fluid presents two distinct layers. If a drop of the ethereal solution is evaporated in a watchglass, the residue is seen, upon inspection through a lens magnifying 100 times, to consist of small, distinct, elongated, and lance-shaped crystals.

4. Concentrated nitric acid dissolves narcotina to a colorless fluid, which acquires a pure yellow tint upon application of heat.

5. Concentrated sulphuric acid dissolves narcotina to a yellow fluid, which turns brown upon application of heat. A solution of narcotina in concentrated sulphuric acid containing a slight admixture of nitric acid, appears of an intense blood-red color, which disappears altogether upon the addition of a somewhat larger amount of nitric acid.

6. If the solution of a salt of narcotina is mixed with chlorine water, it acquires a yellow color, slightly inclining to green; if ammonia is then added, a much more intensely colored, yellowish-red fluid is obtained.

7. If narcotina or one of its salts is dissolved in an excess of dilute sulphuric acid, some finely levigated binoxide of manganese added, the mixture heated to boiling, and kept in ebullition for the space of several minutes, the narcotina absorbs oxygen and is converted into opianic acid, cotarnine (a base soluble in water), and carbonic acid. Ammonia will now of course fail to precipitate narcotina from the filtrate.

1. Crystallized quina (Q + 2 aq.) appears either in the form of fine crystalline needles of silky lustre, which are frequently aggregated into tufts, or as a loose white powder. It is sparingly soluble in cold, but somewhat more readily in hot water. It is readily soluble in spirit of wine, both cold and hot, but less so in ether. The taste of quina is intensely bitter; the solutions of quina manifest alkaline reaction. Upon exposure to heat it loses the 2 eq. of water.

2. Quina neutralizes acids completely. The salts taste intensely bitter; most of them are crystallizable, and for the greater part readily soluble in water and in spirit of wine. Acid solutions reflect a bluish tint.

3. Potassa, ammonia, and the neutral carbonates of the alkalies, produce in solutions of salts of quina (if they are not too dilute) a white,

loose, pulverulent precipitate of hydrated quina, which immediately after precipitation appears opaque and amorphous under the microscope, but assumes, after the lapse of some time, the appearance of an aggregate of crystalline needles. The precipitate redissolves only to a scarcely perceptible extent in an excess of potassa, but more readily in ammonia. It is hardly more soluble in fixed alkaline carbonates than in pure water. If a solution of quina is mixed with ammonia, ether added, and the mixture shaken, the quina which has separated upon the addition of the ammonia, redissolves in the ether, and the clear fluid presents two distinct layers. In this point quina differs essentially from cinchonia; by means of this reaction the former may therefore be readily detected in presence of the latter, and separated from it.

4. Bicarbonate of soda also produces both in neutral and acid solutions of salts of quina a white precipitate. In acidified solutions containing 1 part of quina to 100 parts of acid and water, the precipitate forms immediately;-if the proportion of the quina to the acid and water is as 1 : 150, the precipitate separates only after an hour or two, in the form of distinct needles, aggregated into groups. If the proportion is as 1 : 200, the fluid remains clear, and it is only after from twelve to twenty-four hours' standing that a slight precipitate makes its appearance. The precipitate is not altogether insoluble in the precipitant, and the separation is accordingly the more complete, the less the excess of the precipitant; the precipitate contains carbonic acid.

5. Concentrated nitric acid dissolves quina to a colorless fluid, turning yellowish upon application of heat.

6. The addition of chlorine water to the solution of a salt of quina fails to impart a color to the fluid, or, at least, imparts to it only a very faint tint; but if ammonia is now added the fluid acquires an intensely emerald-green color. If, after the addition of the chlorine water some solution of ferrocyanide of potassium is added, and after this a few drops of ammonia or some other alkali, the fluid acquires a magnificent deep red tint, which, however, speedily changes to a dirty brown. This reaction is delicate and characteristic. Upon addition of an acid* to the red fluid, the color vanishes, but reappears afterwards upon cautious addition of ammonia. (O. Livonius' Letters; A. Vogel.)

7. Concentrated sulphuric acid likewise dissolves pure quina and pure salts of quina to a colorless fluid, which does not acquire any coloration upon being heated to the point of incipient evaporation of the sulphuric acid, but turns afterwards yellow, and finally brown. Sulphuric acid containing an admixture of nitric acid dissolves quina to a colorless or very faint yellowish fluid.

+

c. CINCHONIA, or CINCHONINE (C, H2 N2 O2 = Ci).

§ 233.

24 2

1. Cinchonia appears either in the form of transparent, brilliant, foursided prisms, or fine white crystalline needles, or, when precipitated from concentrated solutions, as a loose white powder. At first it appears tasteless, but after some time the bitter taste of the bark becomes perceptible. It is nearly insoluble in cold water, and dissolves only with

* Acetic acid answers the purpose best.

exceeding difficulty in hot water; it dissolves sparingly in cold dilute spirit of wine, more readily in hot spirit of wine, and the most freely in absolute alcohol. From hot alcoholic solutions the greater portion of the dissolved cinchonia separates upon cooling in a crystalline form. Solutions of cinchonia taste bitter, and manifest alkaline reaction. Cinchonia is insoluble in ether.*

2, Cinchonia neutralizes acids completely. The salts have the bitter taste of the bark; most of them are crystallizable; they are generally more readily soluble in water and in spirit of wine than the corresponding quina compounds. Ether fails to dissolve them.

3. Cinchonia, when heated cautiously, fuses at first without loss of water; subsequently white fumes arise which, like benzoic acid, condense upon cold substances, in the form of small brilliant needles, or as a loose sublimate, a peculiar aromatic odor being exhaled at the same time. If the operation is conducted in a stream of hydrogen gas, long, brilliant prisms are obtained (Hlasiwetz).

4. Potassa, ammonia, and the neutral carbonates of the alkalies produce in solutions of salts of cinchonia a white, loose precipitate of CINCHONIA, which does not redissolve in an excess of the precipitants. If the solution was concentrated, the precipitate does not exhibit a distinctly crystalline appearance, even though viewed through a lens magnifying 200 times; but if the solution was so dilute that the precipitate formed only after some time, it appears under the microscope to consist of distinct crystalline needles aggregated into star-shaped tufts.

5. Bicarbonate of soda and bicarbonate of potassa precipitate cinchonia in the same form as in 4, both from neutral and acid solutions, but not so completely as the simple carbonates of the alkalies. In solutions containing 1 part of cinchonia to 200 parts of water and acid, the precipitate still forms immediately; its quantity increases after standing some time.

6. Concentrated sulphuric acid dissolves cinchonia to a colorless fluid, which upon application of heat first acquires a brown, and finally a black color. Addition of some nitric acid leaves the solution colorless in the cold, but upon application of heat the fluid, after passing through the intermediate tints of yellowish-brown and brown, turns finally

black.

7. The addition of chlorine water to the solution of a salt of cinchonia fails to impart a color to the fluid; if ammonia is now added, a yellowish-white precipitate is formed.

Recapitulation and Remarks.

§ 234.

The alkaloids of the second group are altered or precipitated by various other reagents besides those mentioned above; the reactions are, however, not adapted to effect their individual detection and separation. Thus, for instance, bichloride of platinum produces in solutions of the salts of the three alkaloids belonging to this group, a yellowish

* The cinchonia of commerce usually contains in admixture another alkaloid, called cinchotina, which is soluble in ether. This alkaloid crystallizes in large rhomboidal crystals of brilliant lustre, which fuse at a high temperature, and cannot be sublimed, even in a stream of hydrogen gas (Hlasiwetz).

white precipitate, chloride of mercury a white precipitate, tincture of galls a yellowish-white, flocculent precipitate, &c.

Narcotina and quina being soluble in ether, whilst cinchonia is insoluble in that menstruum, the former may be most readily separated by this means from the latter alkaloid. For this purpose the analyst need simply mix the solution of the three alkaloids with ammonia in excess, then add ether, and separate the solution of quina and narcotine from the undissolved cinchonia. If the ethereal solution is now evaporated, the residue dissolved in hydrochloric acid and a sufficient amount of water to make the dilution as 1: 200, and bicarbonate of soda, is then added, the narcotina precipitates, whilst the quina remains in solution. By evaporating the solution, and treating the residue with water, the quina is obtained in the free state.

THIRD GROUP.

NON-VOLATILE ALKALOIDS WHICH ARE PRECIPITATED BY POTASSA FROM THE SOLUTIONS OF THEIR SALTS, AND DO NOT REDISSOLVE TO A PERCEPTIBLE EXTENT IN AN EXCESS OF THE PRECIPITANT; BUT ARE NOT PRECIPITATED FROM (even somewhat concentrated) ACID SOLUTIONS BY THE BICARBONATES OF THE FIXED ALKALIES: Strychnia, Brucia, Veratria.

+

a. STRYCHNIA, or STRYCHNINE (CH2 N ̧ O ̧ = Sr).

§ 235.

44

1. Strychnia appears either in the form of white, brilliant rhombic prisms, or, when produced by precipitation or rapid evaporation, as a white powder. It has an exceedingly bitter taste. It is nearly insoluble in cold, and barely soluble in hot water. It is insoluble in absolute alcohol and ether, and difficultly soluble in dilute spirit of wine. It does not fuse when heated. It is exceedingly poisonous.

2. Strychnia neutralizes acids completely. The salts of strychnia are, for the most part, crystallizable; they are soluble in water. All the salts of strychnia have an intolerably bitter taste and are exceedingly poisonous.

3. Potassa and carbonate of soda produce in solutions of salts of strychnia white precipitates of strychnia, which are insoluble in an excess of the precipitants. Viewed through a lens magnifying one hundred times the precipitate appears as an aggregate of small crystalline needles. From dilute solutions the strychnia separates only after the lapse of some time, in the form of crystalline needles, which are distinctly visible even with the naked eye.

The preci

4. Ammonia produces the same precipitate as potassa. pitate redissolves in an excess of ammonia, but after a short time-or if the solution is highly dilute, after a more considerable lapse of time-the strychnia crystallizes from the ammoniacal solution in the form of needles, which are distinctly visible with the naked eye.

5. Bicarbonate of soda produces in neutral solution of salts of strychnia a precipitate of strychnia, which separates in fine needles shortly after the addition of the reagent, and is insoluble in an excess of the precipitant. But upon adding one drop of acid (so as to leave the fluid still alkaline) the precipitate dissolves readily in the liberated carbonic acid.