The symptoms in rabbits are profuse nasal secretion and salivation with paralysis, as in frogs. Applied to the eye, neurine causes contraction of the pupil; to a less degree the same effect is produced by the ingestion of neurine.
Trimethyloxyammonium hydrochloride causes similar symptoms to neurine, but the action is less powerful.—V. Cervello, Arch. Ital. Biol., vii. 232-233.
§ 676. Betaine.—Betaine may be separated from a solution in alcohol as large deliquescent crystals; the reaction of the crystals is neutral. Distilled with potash, trimethylamine and other bases are formed.
Betaine chloride, C5H12NO2Cl, forms plates permanent in the air and insoluble in absolute alcohol. A solution of the chloride in water gives, with potassium mercuric iodide, a light yellow or whitish yellow precipitate, soluble in excess; but, on rubbing the sides of the tube with a glass rod, the oily precipitate crystallises as yellow needles; probably this is characteristic.
The aurochloride (Au = 43·1 percent.) forms fine cholesterine plates, soluble in water; melting-point 209°. Betaine is not poisonous.
§ 677. Peptotoxine.—Brieger submitted to the action of fresh gastric juice moist fibrin for twenty-four hours at blood heat. The liquid was evaporated to a syrup and boiled with ethylic alcohol, the ethylic alcohol was evaporated, the residue digested with amylic alcohol, and the amyl alcohol in its turn evaporated to dryness; the residue was a brown amorphous mass that was poisonous. It was farther purified by treating the extract with neutral lead acetate and then filtered; the filtrate was freed from lead by SH2 and treated with ether, the ethereal extract being then separated and evaporated to dryness; this last residue was taken up with amyl alcohol, the alcohol evaporated to dryness, and the residue finally taken up with water and filtered. The filtrate is poisonous. The poisonous substance, to which Brieger gave the provisional name of peptotoxine, is a very stable substance, resisting the action of a boiling temperature, and even the action of strong alkalies. It gives precipitates with alkaloidal group reagents, and strikes a blue colour with ferric chloride and ferricyanide of potassium. The most characteristic test seems to be its action with Millon’s reagent (a solution of mercury nitrate in nitric acid containing nitrous acid); this gives a white precipitate which, on boiling, becomes intensely red.
It is poisonous, killing rabbits in doses of 0·5 grm. per kilogrm., with symptoms of paralysis and coma. The nature of this substance requires further elucidation.
§ 678. Pyridine Alkaloid from the Cuttle Fish.—O. de Coninck[669] has obtained, by Gautier’s process, an alkaloid from the cuttle fish, of the formula C8H11N, in the form of a yellow, mobile, strongly odorous liquid, very soluble in alcohol, ether, and acetone, boiling-point 202°. It quickly absorbs moisture from the air. It forms two mercuric chlorides, one of which has the formula (C8H11N,HCl)2HgCl2; this compound crystallises in small white needles, slightly soluble in water and dilute alcohol, but insoluble in absolute alcohol, and decomposing when exposed to moist air. The other salt is a sesqui-salt, forming long yellowish needles, insoluble in ordinary solvents, and decomposing when exposed to moist air. The alkaloid also forms deliquescent very soluble salts with hydrochloric and hydrobromic acids. A platinum salt is also formed, (C8H11N)2H2PtCl6; it is of a deep yellow colour, almost insoluble in cold, but soluble in hot water; it is decomposed by boiling water, with the formation of a very insoluble compound in the shape of a brown powder, (C8H11N)2PtCl4. Coninck’s alkaloid, on oxidation with potassic permanganate, yields a gummy acid; this acid, on purifying it by conversion into a potassium salt and then into a cupric salt, was found to be nicotinic acid; so that the alkaloid is undoubtedly a pyridine compound; indeed, the acid, distilled with lime, yields pyridine.