§ 307. Stas’s Process.—The original method of Stas[325] (afterwards modified by Otto)[326] consisted in extraction of the organic matters by strong alcohol, with the addition of tartaric acid; the filtered solution was then carefully neutralised with soda, and shaken up with ether, the ethereal solution being separated by a pipette. Subsequent chemists proposed chloroform instead of ether,[327] the additional use of amyl-alcohol,[328] and the substitution of acetic, hydrochloric, and sulphuric for tartaric acid.
[325] Annal d. Chem. u. Pharm., 84, 379.
[326] Ib., 100, 44. Anleitung zur Ausmittel. d. Gifte.
[327] Rodgers and Girwood, Pharm. Journ. and Trans., xvi. 497; Prollin’s Chem. Centralb., 1857, 231; Thomas, Zeitschr. für analyt. Chem., i. 517, &c.
[328] Erdmann and v. Ushlar, Ann. Chem. Pharm., cxx. pp. 121-360.
COLOUR REACTIONS[329] OF CERTAIN ALKALOIDS.
| Name of Substance. | Strong Sulphuric Acid. | Fröhde’s Reagent. | Mandelin’s Reagent. |
|---|---|---|---|
| Strychnine. | ... | ... | Violet-blue, then lastly cinnabar-red. |
| Brucine. | Pale red. | Red, then yellow. | Yellow-red to orange, afterwards blood-red. |
| Curarine. | Fine red. | ... | ... |
| Quinine. | ... | Greenish. | Weak orange, then blue-green, lastly green-brown. |
| Atropine. | ... | ... | Red, then yellow-red, and lastly yellow. |
| Aconitine. | ... | ... | ... |
| Veratrine. | Yellow, then orange, blood-red, lastly carmine-red. | Gamboge-yellow, then cherry-red. | Yellow, orange, blood-red, lastly carmine-red. |
| Morphine. | ... | Violet, green, blue-green, and yellow. | Reddish, then blue-violet. |
| Narcotine. | Yellow, then raspberry colour. | Green, then brown-green, yellow, lastly red. | Cinnabar-red, then carmine-red. |
| Codeine. | ... | Dirty green, then blue, lastly yellow. | Green-blue to blue. |
| Papaverine. | ... | Green, then blue-violet, lastly cherry-red. | Blue-green to blue. |
| Thebaine. | Blood-red, then yellow-red. | Orange, then colourless. | Red to orange. |
| Narceine. | Grey-brown, then blood-red. | Brown, green, red, lastly blue. | Violet, then orange. |
| Nicotine. | ... | Yellowish, then red. | Transitory dark colour. |
| Coniine. | ... | Yellow. | ... |
| Colchicine. | Intense yellow. | Yellow to green-yellow. | Blue-green, then brown. |
| Delphinidine. | Red. | Red-brown. | Red-brown to brown. |
| Solanine. | Red-yellow, then brown. | Cherry-red, red-brown, yellow, yellow-green. | Yellow-orange, cherry-red, and lastly violet. |