acidulated with sulphuric acid and then supersaturated with ammonia, aconitia and quinidia are precipitated; while atropia, codeina, hyoscyamia, and physostigmia are (for a brief time) dissolved. The aconitia and quinidia precipitate being dissolved in hydrochloric acid, platinic chloride precipitates only the quinidia.

The watery alkaline residue of G is now acidulated with sulphuric acid and washed at about 55° C. with amylic alcohol; then made alkaline with ammonia and extracted with amylic alcohol at the same temperature. If the residue of a portion of the solvent is colored, the alkaloids are extracted from the whole by acidulated water; and again extracted by amylic alcohol in presence of alkali (as directed for F and G). Solution H (in amylic alcohol) contains Morphia, Narceina, Solania.-Narceina is dissolved from the residue by warm water.

The watery alkaline residue of H, which may be termed solution I, may contain Curarin, and traces of Berberina (Digitalin) and Narceina. The solution (I) evaporated to dryness, with pulverized glass, yields its alkaloids to alcohol.

(7) Separation of Alkaloids and Glucosides from each other. Dragendorff's scheme. Use of the solvents and operations employed in (6).

A. Benzole dissolves, from acid (sulphuric) aqueous solutions -Caffeina, Colchicin (incompletely), Colocynthin, Cubebin, Delphina (incompletely), Digitalin, Elaterin, Narceina, Piperin, Syringin and traces of physostigmia and veratria.

B. Benzole dissolves, from alkaline (ammoniacal), aqueous solutions-Aconitia, Atropia, Brucia, Cinchonia, Codeina, Conia, Delphina, Emetia, Hyoscyamia, Narceina (imperfectly), Narcotina, Nicotia, Papaverina, Physostigmia, Quinia, Quinidia, Strychnia, Thebaina, Veratria.

c. Benzole fails to dissolve, more than traces, from alkaline solutions-Morphia, Salicin, Solania, Syringin, Theobromina.

D. Benzole does not dissolve, either from acid or alkaline water solutions-Curarin, Pierotoxin, Salicin, Theobromina.

E. Benzole, Petroleum Naphtha, Amylic Alcohol, and Chloroform, all fail to dissolve, from acid or alkaline solutions, Curarin.

F. Amylic alcohol dissolves, from acid (sulphuric) water solutions, more readily when warm-Aconitia (very sparingly), Berberina (in greater part), Brucia (in traces), Caffeina, Cantharidin, Colchicin, Cubebin, Delphina, Digitalin, Narceina (sparingly), Narcotina, Picrotoxin, Piperin, Salicin, Santonin, Theobromina, Veratria.

G. Petroleum Naphtha leaves undissolved, from acid or alkaline solutions—Aconitia, Berberina, Caffeina, Curarin, Narceina, Salicin, Syringin, Physostigmia, Theobromin.

H. Petroleum Naphtha dissolves from acid (sulphuric) watery solutions-Piperin, Populin.

1. Petroleum Naphtha dissolves from alkaline (ammoniacal) solutions-Brucia, Conia, Emetia, Nicotia, Papaverina, Quinia, Strychnia, Veratria, and traces of aconita, berberina, cinchonia, delphina, narcotina.

J. Petroleum Naphtha does not dissolve, from alkaline solution-Caffeina, Colchicin, Delphina.

K. Chloroform dissolves from the acid (sulphuric) water solution-Caffeina, Colchicia, Colocynthin, Cubebin, Delphina (sparingly), Digitalin, Narcotina, Papaverina, Piperin, Picrotoxin, Santonin, Thebaina, Theobromina.

L. Chloroform dissolves from the alkaline (ammoniacal) water solution-Aconitia, Atropia, Berberina (sparingly), Brucia, Caffeina, Cinchonia, Codeina, Colchicin, Conia, Cubebin, Delphina, Digitalin, Emetia, Hyoscyamia, Morphia (sparingly), Narcotina, Narceina (sparingly), Nicotia, Papaverina, Piperin, Quinia, Strychnia, Thebaina, Theobromina, Veratria.

(8) Separation of certain alkaloids from each other by solubility in alkali.

A. Solutions of Fixed Alkalies precipitate, and by excess redissolve, in dilute solution-Atropia, Berberina, Codeina,

Conia, Hyoscyamia (partly), Morphia, Nicotia, Solania—Colchicin being decomposed.

Most of the other well-known alkaloids are left in precipitate by excess of fixed alkali.

B. Of those not redissolved by fixed alkalies, Ammonia in strong excess dissolves from precipitate-Aconitia, Colchicin, Hyoscyamia, Physostigmia, Strychnia.

(9) Separation by successive use of Ether, Water (and Chloroform). The alkaloids are previously obtained pure, as bases, and in the solid state finely divided. The ether used is absolute, applied in proportion of 40 to 60 parts to one of the solid, with agitation and digestion in a stoppered flask. The water is applied hot, and in proportion of fully 100 parts to one of solid. The chloroform should be nearly or quite free from alcohol, and 20 to 40 parts used. Alkaloids which are appreciably divided by the solvents have their names placed in parentheses.

135. Detection and separation of alkaloids as a class. The material is obtained in solution, and free from albumenoid, gelatinoid, gummy, coloring, and "extractive" substances. Also, the presence of inorganic acids, bases, or salts which react with the several reagents, must be avoided. Then, the alkaloids are precipitated-by potassio mercuric iodide (also a means of volumetric determination) (a); by phosphomolybdic acid (permitting a division of alkaloids by subsequent use of ammonia) (b); by metatungstic acid (c); by potassio cadmic iodide (d); by picric acid (with distinguishing exceptions) (e); by tannic acid (with exceptions and peculiarities) (f); by solution of iodine with iodide (g).

a. The potassio mercuric iodide reagent is prepared by adding to solution of mercuric chloride enough potassic iodide to dissolve the precipitate first formed. It gives precipitates in even dilute solutions of nearly all alkaloids except Caffeina, Colchicin, Digitalin, Theobromina; the precipitates being mostly yellowish-white. For the reactions with the Volatile Alkaloids and Ammonia, see 131. The precipitates are insoluble in acids (distinction from ammonia), or in dilute alkalies, but soluble in alcohol and (in many cases) in ether-also, in many cases, soluble in excess of the precipitant. For the extraction of the alkaloid from the precipitate, triturate the latter with stannous chloride and enough potassa solution to give a strong alkaline reaction, then exhaust with ether or chloroform, or, if the alkaloid is not soluble in these, add potassic carbonate instead of potassa and extract with strong alcohol.

For the volumetric determination by potassio mercuric iodide (MAYER), the reagent is prepared with 13.55 grams mercuric chloride, 5 grams potassic iodide, and water to one litre. Of this standard solution, 1 c.c. precipitates, of each alkaloid, the quantities stated below:

The volumetric determination is somewhat unsatisfactory, by reason of the slowness with which the precipitate subsides. The alkaloid solution is slightly acidulated with sulphuric or hydrochloric acid; after each addition of the reagent the mixture is strongly shaken and left to subside; then a drop of the clear liquid is placed on a blue or black glass plate, and treated with a drop of the reagent to learn whether further addition is necessary.

b. Phosphomolybdic acid solution *-SONNENSCHEIN's Reagent gives amorphous and mostly yellow precipitates with the alkaloids, as below. The alkaloid solution should be neutral or slightly acid, as alkalies dissolve the precipitate in most cases. The reaction with ammonia should be noted ten minutes after its addition.

* The yellow precipitate formed on mixing acid solutions of molybdate of ammonium and phosphate of sodium-the phosphomolybdate of ammonium-is well washed, suspended in water, and heated with carbonate of sodium until completely dissolved. The solution is evaporated to dryness, and the residue gently ignited till all ammonia is expelled (sodium being substituted for ammonium). If blackening occurs, from reduction of molybdenum, the residue is moistened with nitric acid and heated again. It is then dissolved with water and nitric acid to strong acidulation; the solution being made ten parts to one of residue. It must be preserved from contact with vapor of ammonia.