Case of recovery from a poisonous dose of strychnia; with observations on the tests for organic alkalies / [Thomas Anderson].

  • Thomas Anderson
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: Case of recovery from a poisonous dose of strychnia; with observations on the tests for organic alkalies / [Thomas Anderson]. Source: Wellcome Collection.

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    times consist almost entirely of isolated six-sided tables, of great regularity. The precipitate dissolves readily in hot water, and is deposited, as the solution cools, in irregular plates. Quinine—gives, with ammonia, a perfectly amorphous precipi¬ tate, but with sulphocyanide of potassium it gives small irregular groups of acicular crystals, which bear a resemblance to those pro¬ duced by strychnia, but are longer and more irregular (Fig. 9). When the precipitate is produced in a test Fis-9- tube, and with a concentrated solution, it falls immediately as a white powder com¬ posed of extremely minute needles; but when the solution is dilute, it is deposited, after the lapse of twenty-four hours, in crystals from a quarter to a, third of an inch in length. Lepage, under the same circumstances, states that he obtained a mass of yellowish green crystals, but I have always obtained them perfectly white. This is, of all those which I have examined, the salt which approaches most nearly in its characters to the strychnia compound, but it differs from it in the length of time required for its production in a dilute solution; and if we combine with its cha¬ racters the amorphous precipitate which quinine affords with am¬ monia, we are able at once to distinguish the one base from the other. jBebeerine—is precipitated amorphous both by ammonia and sul¬ phocyanide of potassium. The latter precipitate is formed even in highly dilute solutions at the instant of mixture, and is a delicate test of the presence of that alkaloid, although quite inapplicable as a means of distinguishing it from others. Atropine—is precipitated in the amorphous state by ammonia, and not at all by sulphocyanide of potassium. It must be obvious from the observations now detailed, that under the microscope the forms of the different alkaloids examined are very characteristic and distinct, and that the combined observation of the base itself and of its sulphocyanide, may be considered as perfectly distinctive of the common alkaloids. I have not yet, how¬ ever, had time to ascertain how far the method may be applicable to the detection of the substances containing those alkaloids, by ex¬ tracting them with an acid, and examining the precipitates obtained from the fluid. It is unquestionable, however, that the regularity of the crystals would under such circumstances be impaired, although it is possible that their characteristics might be retained with suffi¬ cient completeness. However this may be, any addition to the tests for the pure alkaloids is a matter of importance; and I think the present communication may not be altogether without value, as adding something to the means of distinguishing a class of sub¬ stances so poorly characterised by their ordinary chemical reactions as the organic alkalies.
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