nearly to dryness. Conduct this process either under a bell-glass over sulphuric acid, with or without rarefaction of the air, or in a tubulated retort, through which a current of air is passed. If fatty or other insoluble matters separate in the process of concentration, pass the concentrated fluid through a moistened filter, and evaporate the filtrate nearly to dryness, conducting the process, as above, either under a bell-glass or in a retort.

c. Digest the residue with cold absolute alcohol, filter, wash the insoluble residue thoroughly with alcohol, and let the alcoholic solution evaporate in the air or in vacuo; dissolve the acid residue in a little water, and add bicarbonate of soda as long as efferves

cence ensues.

d. Add to the mixture four or five times its volume of pure ether, free from oil of wine, and shake; then allow it to stand at rest, and let a little of the supernatant ether evaporate spontaneously on a watch-glass. If this leaves oily streaks upon the glass, which gradually collect into a drop, and emit, upon the application of a gentle heat a disagreeable, pungent, and stilling odor, there is reason to infer the presence of a liquid volatile base; whilst a solid residue or a turbid fluid, with solid particles suspended in it, indicates a non-volatile, solid base. In the latter case the base may emit a disagreeable animal smell, but not a pungent odor, as is the case with volatile bases. The blue color of reddened litmus-paper is permanently restored. If no residue is left, add to the fluid some solution of soda or potassa, and shake with repeatedly renewed ether, which will now dissolve the base. It follows from the assumption that the bases present will pass into the ethereal solution, that Stas's method is principally calculated for the detec tion of the poisonous alkaloids which are soluble in ether, though some of them only sparingly. The following are the vegeto-alkalies which Stas enumerates as discoverable by his method: Conia, Nicotina, Aniline, Picoline, Petinine, Morphia, Codeia, Brucia, Strychnia, Veratria, Colchicia, Delphia, Emetine, Solania, Aconitina, Atropia, and Hyoscyamia.

a. There is reason to infer the presence of a volatile base.

Add to the contents of the vessel from which you have taken the small portion of ether for evaporation on the watch-glass, one or two cubic centimetres of strong solution of potassa or soda, shake the mixture, let it stand at rest, pour the supernatant fluid into a flask, and treat the residue again three or four times with ether, until the last portion poured off leaves no longer a residue upon evaporation. Mix the ethereal fluid now with some dilute sul phuric acid (1 part of acid to 5 parts of water) until the well-shaken fluid manifests acid reaction; allow the mixture to stand at rest, decant the supernatant ether from the acid aqueous fluid, and treat the latter once more with ether in the same way.

aa. Mix the residual acid solution (which may contain sulphates of ammonia, nicotina, aniline, picoline, and petinine— indeed which must contain these bases, if they are present in the examined substance, since their compounds with sulphuric acid are quite insoluble in ether; and in which, if conia is present, the greater part of the latter alkaloid is also found) with concentrated solution of soda or potassa in excess, and treat with ether, which will again dissolve the liberated bases; decant the ether, and leave it to spontaneous evaporation, at the lowest possible temperature; place the dish with the resi due in vacuo over sulphuric acid. In this process the ether and ammonia escape, leaving the volatile organic base in the pure state. The nature of the organic base is then finally ascertained.

bb. The ether decanted from the acid solution contains the animal matters which it has removed from the alkaline fluid. It leaves, therefore, upon spontaneous evaporation, a trifling faint yellow residue of nauseous odor, which contains also some sulphate of conia, if that base was present in the examined

matter.

B. There is reason to infer the presence of a solid base.

Add a few drops of alcohol to the ethereal solution obtained by treating with ether the previously acid residue mixed either simply with bicarbonate of soda, or first with that reagent, then with solution of soda or potassa (see c and d), and leave the mixture to spontaneous evaporation. If this fails to give the base in a distinctly crystalline form and sufficiently pure, add a few drops of water slightly acidified with sulphuric acid, which will usually serve to separate the mass into a fatty portion, adhering to the dish, and an acid aqueous solution, which contains the base as an acid sulphate. Decant or filter, wash with a little slightly acidified water, and evaporate the solution to a considerable extent, under a bellglass over sulphuric acid. Mix the residue with a highly concentrated solution of pure carbonate of potassa, treat the mixture with absolute alcohol, decant, and let the alcoholic fluid evaporate, which will generally leave the base in a state of perfect purity, or nearly so.

2. OTTO's MODIFICATIONS OF STAS'S METHOD.*

a. In the method just described, the morphia which may be present will only pass into the ethereal solution if the solution obtained in 1, c, is shaken with ether immediately after the addition of the bicarbonate of soda, and the ether then quickly decanted. But if the operation of shaking with ether is delayed, so as to af

* Annal. d. Chem. u. Pharm., 100, 44

ford the morphia time to crystallize, the crystals will deposit, being almost absolutely insoluble in ether (P. PÖLLNITZ); and if the ethereal solution is allowed to stand some time, the dissolved morphia will separate in small crystals, on the sides of the vessel.-As it is therefore, under the circumstances stated, always likely to happen that the morphia may remain, wholly or in part, undissolved by the ether, it is of the highest importance never to neglect mixing the alkaline fluid obtained in 1, d-after repeated extraction with ether, and subsequent addition of some solution of soda, to dissolve the morphia, which may have separated, and after evaporating the ether still present-with a concentrated solution of chloride of ammonium, and letting the mixture stand exposed to the open air, to allow the morphia to crystallize.

b. Instead of the process described in 1, 2, to effect the detection of non-volatile alkaloids, Orrо recommends the following method, which is in principle the same as that recommended by STAS for the detection of the volatile bases.

Let the ethereal solution evaporate, dissolve the residuary impure alkaloid in a little water mixed with sulphuric acid, and shake the solution repeatedly with ether, which will remove the foreign organic matters present, and leave the acid vegeto-alkaline sulphate unaffected. Mix now the acid aqueous solution with carbonate of soda in excess, shake repeatedly with ether (to dissolve the liberated alkaloids), and let the ethereal solution evaporate, when the alkaloids held in solution by the ether will be left in a very pure state and, to a great extent, in the crystalline form. This method has stood the test of numerous experiments.

c. But what Orтo recommends most, is the treatment with ether of the alkaloid in the form of salt, before its separation, by means of an alkali, and its solution in ether.-If, therefore, you wish to follow this method, shake the acid aqueous fluid of 1, c, which contains the alkaloid in combination with tartaric acid or oxalic acid, repeatedly with ether, so long as the ether becomes colored and leaves a residue upon evaporation; then, and not before, add carbonate of soda, dissolve the alkaloid by means of ether, and proceed generally as directed in 1, d. Upon evaporating the ether, the alkaloid is now left at once in a very pure state.

3. METHOD OF L. V. USLAR AND J. ERDMANN.*

This may be considered an improvement upon STAS's method, as regards non-volatile alkaloids, more especially morphia, whilst STAS'S method deserves the preference for volatile alkaloids. The new method is the same in principle as that of STAS's, simply sub stituting amyl-alcohol for ether.

* Annal. d. Chem. u. Pharm., 120, page 121; and 122, page 360.

Mix the matters to be examined with water, if necessary, to the consistence of a thin paste, acidify slightly with hydrochloric acid, digest one or two hours at from 140° to 176° Fah., and pass through a linen cloth moistened with water. Extract the residue with water acidified with hydrochloric acid, add the solution obtained to the first fluid, supersaturate with ammonia, and evaporate to dryness, with addition of pure quartz sand, which will enable you to reduce the residue to powder. Boil the powder repeatedly with amyl-alcohol, to extract the whole of the alkaloid from it. Filter the extracts hot through paper moistened with amyl-alcohol. The filtrate, which is mostly colored yellow, holds, besides the alkaloid, fatty and coloring matters in solution. To remove these latter, transfer the filtrate to a cylindrical vessel, mix it with from ten to twelve times its volume of almost boiling water, acidified with hydrochloric acid, and vigorously shake the mixture for some time. The hydrochlorate of the alkaloid passes into the aqueous solution, whilst the fatty and coloring matters remain dissolved in the amylalcohol.* Remove the latter by means of an India-rubber pipette, then shake the acid solution repeatedly with fresh quantities of amyl-alcohol, until all the fatty and coloring matters are completely removed. Concentrate now by evaporation, mix with ammonia in slight excess, add hot amyl-alcohol, and shake vigorously. When the liquid has separated into two distinct layers, draw off, by means of a pipette, the upper layer, which contains the solution of the alkaloid in amyl-alcohol, treat the fluid once more with hot amylalcohol, then completely drive off the latter by heating on the waterbath, which will often leave the alkaloid sufficiently pure for examination by the usual reactions. Should it, however, still look yellowish or brownish, dissolve it once more in dilute hydrochloric acid, shake the solution with amyl-alcohol, remove the latter with the pipette, then, supersaturate with ammonia, shake again with amyl-alcohol, draw off the latter with the pipette, and evaporate it on the water-bath. It is only in very rare cases that the alkaloid left by this evaporation requires a repetition of this process of purification. The last evaporation of the pure alkaloid is best conducted in a small porcelain crucible, placed obliquely. Before proceeding to the decisive reaction, pour a few drops of concentrated sulphuric acid over the alkaloid, and observe whether it still turns brown on the application of this test; in which case the process of purification must be repeated.-USLAR and ERDMANN have detected and isolated by this method very minute traces of

*If less water is used, traces of the hydrochlorate of the alkali are apt to remain in the amyl-alcoholic solution. J ERDMANN recommends always to put aside the first portion of amyl-alcohol, as well as that used to effect the removal of the fatty matters that they may, if necessary, be shaken once more with the stated quantity of acidulated water.

alkaloids, e.g., 5 milligrammes of hydrochlorate of morphia, 1 drop of nicotine, 9 milligrammes of strychnine, mixed with from 2 to 3 pounds of contents of the stomach. In his second paper on the subject ERDMANN calls particular attention to the fact that he suc ceeded in separating by this method the poisonous alkaloids from quite putrid intestines of poisoned animals, from a fortnight to a month after death. The latter experiments referred to strychnia and morphia. Of course only those portions of the alkaloids can be detected which have not yet suffered decomposition. With regard to morphia, there would seem to exist no doubt but that this alkaloid suffers decomposition in the organism. A rabbit had given it 0.1 grm. of hydrochlorate of morphia, and was killed three and a half hours after: no morphia was found in the urine, brain, and spinal marrow; only very little of it in the blood, a little in the stomach and the small intestines, more in the other intestines.

4. METHODS OF DETECTING STRYCHNIA, BASED UPON THE Use of CHLOROFORM.*

a. RODGERS AND GIRDWOOD'S METHOD.†

Digest the substance under examination with dilute hydrochloric acid (1 part of acid to 10 parts of water) and filter; evaporate the filtrate on the water-bath to dryness, extract the residue with spirit of wine, evaporate the solution, treat the residue with water, filter, supersaturate the filtrate with ammonia, add oz. (15 grammes) of chloroform, shake, transfer the chloroform to a dish, by means of a pipette, evaporate on the water-bath, moisten the residue with concentrated sulphuric acid, to effect carbonization of foreign organic matters, treat with water, after the lapse of several hours, then filter. Supersaturate the filtrate again with ammonia, and shake it with about 1 drachm (4 grammes) of chloroform. Repeat the same operation until the residue left upon the evaporation of the chloroform is no longer charred by sulphuric acid. Transfer the chloroform solution which leaves a pure residue, no longer affected by sulphuric acid, drop by drop, by means of a capillary tube, to the same spot on a heated porcelain dish, letting it evaporate, then test the residue with sulphuric acid and chromate of potassa. RODGERS and GIRDWOOD succeeded in detecting by this method so small a quantity of strychnia as the 'oth part of a grain.

*These methods are no doubt useful also for effecting the separation of other alka loids; however, the deportment of the latter with chloroform has not yet been sufficiently studied.

497.

LIEBIG and KOPP's "Jahresbericht," 1857, 603.-Pharm. Journ. Trans., xvi