[455] Brucin u. Strychnin; eine toxikologische Parallele, von Dr. F. A. Falck. Vierteljahrsschr. f. gerichtl. Med., Band xxiii. p. 78.
TABLE SHOWING THE LETHAL DOSES OF VARIOUS TETANISING POISONS.
| Minimum Lethal Dose for every Kilogram Weight of Rabbit. | Proportional Strength. | ||
|---|---|---|---|
| Mgrms. | |||
| Strychnine nitrate, | 0·6 | ... | |
| Thebaine nitrate, | 14·4 | 24 | ·0 |
| Brucine nitrate, | 23·0 | 38 | ·33 |
| Landanine nitrate, | 29·6 | 49 | ·33 |
| Codeine nitrate, | 51·2 | 85 | ·33 |
| Hydrocotarnine nitrate, | 203·8 | 339 | ·66 |
If these views are correct, it follows that the least fatal dose for an adult man would be 1·64 grm. (about 24·6 grains) of brucine nitrate.
Brucine Crystals. (From a Photograph.)
§ 403. Tests.—If to a solution of brucine in strong alcohol a little methyl iodide is added, at the end of a few minutes circular rosettes of crystal groups appear (see [fig.]): they are composed of methyl brucine iodide (C23H25(CH3)N2O4HI). Crystals identical in shape are also obtained if an alcoholic solution of iodine, or hydriodic acid with iodine, is added to an alcoholic solution of brucine. A solution of strychnine gives with methyl iodide no similar reaction. Strychnine in alcoholic solution, mixed with, brucine in no way interferes with the test. The methyl iodide test may be confirmed by the action of nitric acid. With that reagent it produces a scarlet colour, passing into blood-red, into yellow-red, and finally ending in yellow. This can be made something more than a mere colour test, for it is possible to obtain a crystalline body from the action of nitric acid on brucine. If a little of the latter be put in a test-tube, and treated with nitric acid of 1·4 specific gravity (immersing the test-tube in cold water to moderate the action), the red colour is produced. On spectroscopic examination of the blood-red liquid a broad, well-marked absorption band is seen, the centre of which (see [page 55]) is between E. & F. [W. L. about 500]. There is also a development of nitric oxide and carbon dioxide, and the formation of methyl nitrite, oxalic acid, and kakotelin (C23H26N2O4 + 5NHO3 = C20H22N4O9 + N(CH3)O2 + C2H2O4 + 2NO + 2H2O). On diluting abundantly with water, the kakotelin separates in yellow flocks, and may be crystallised out of dilute hydrochloric or dilute nitric acid in the form of yellow or orange-red crystals, very insoluble in water, but dissolving readily in dilute acid. On removal by dilution of the product just named, neutralisation with ammonia, and addition of a solution of chloride of calcium, the oxalate of lime is thrown down. The nitric acid test is, therefore, a combined test, consisting of—the production by the action of nitric acid (1) of a red colour; (2) of yellow scales or crystals insoluble in water; (3) of oxalic acid. No alkaloid save brucine is known to give this reaction.
There are other methods of producing the colour test. If a few drops of nitric acid are mixed with the substance in a test-tube, and then sulphuric acid cautiously added, so as to form a layer at the bottom, at the junction of the liquids a red zone, passing into yellow, is seen.