Benzol.—All the poisonous alkaloids, except solanine, are soluble in benzol.
Chloroform.—Solanine (50,000); morphine (6550); strychnine (8); the rest freely soluble.
Ether.—Solanine (9000); morphine (7725); strychnine (1400); aconitine (777); brucine (440); veratrine (108); atropine, picrotoxin,[26] and digitalin, very soluble.
[26] Digitalin and picrotoxin, although not alkaloids, are inserted in the above list, because they have a general similarity in chemical properties to them; and for the convenience of the toxicologist.
Water (cold).—Strychnine (8333); veratrine (7860); morphine (4166); aconitine (1783); solanine (1750); brucine (900); atropine (414); picrotoxin (150); digitalin very soluble.
The principal Alkaloids and their Salts, in the state of powder, or with ‘conia’ and ‘nicotia,’ in the state of an oily looking liquid, may be thus distinguished:—
1. a. The powder is treated with nitric acid:—It is coloured red; probable presence of Brucia, Delphia, Morphia, or commercial Strychnia. If the reddened acid becomes violet on the addition of ‘protochloride of tin,’ it is Brucia; if it becomes black and carbonaceous, it is Delphia. If the powder is fusible without decomposition, and strongly decomposes iodic acid, it is Morphia; if it is not fusible without decomposition, and does not decompose iodic acid, it is Strychnia.
b. If instead of a red, the powder strikes a green colour with nitric acid, it is Solania; if it is insoluble in ‘ether,’ and not reddened by ‘nitric acid,’ it is Emetia; if soluble in ether, not reddened by ‘nitric acid,’ but melts and volatilises when heated, it is Atropia; if it is thus affected by ether or nitric acid, but does not volatilise, it is Veratria. (See 2, below.)
2. a. The powder, or (with ‘conia and nicotia’) concentrated liquor, is treated with a drop or two of concentrated sulphuric acid:—A red colour is produced; probable presence of Brucia, Nicotina, Salicine, or Veratria. If the reddened mixture has at first a roseate hue, turning deep red on the addition of nitric acid, it is Brucia; if the original substance moistened with solution of potassa evolves the odour of tobacco, it contains Nicotine; if the red colour produced by the acid is permanent and of an intense blood-hue, and the powder agglutinates into lumps like resin, it is Salicine; if the colour is at first yellowish, changing to blood-red, and ultimately to crimson and violet, it is Veratria.
b. If instead of the substance being ‘reddened’ by strong sulphuric acid, no particular action ensues in the cold, it contains either Conia or Strychnia; if a small fragment of bichromate of potassa being now dropped in, produces a rich violet colour, it is Strychnia; if the original matter on being heated, or treated with solution of potassa, evolves a penetrating, disagreeable odour, somewhat analogous to that from ‘hemlock,’ or to a mixture of those from tobacco and mice, it is Conia.