The chemistry of the bark of Robina pseud-acacia, Linné (false acacia or common locust) / by Frederick B. Power.

  • Frederick Belding Power
Date:
[1901]
Catalogue details

Licence: In copyright

Credit: The chemistry of the bark of Robina pseud-acacia, Linné (false acacia or common locust) / by Frederick B. Power. Source: Wellcome Collection.

    15/30 page 11
    aromatic odour was developed, thus indicating the presence of a glucoside. A larger quantity of the bark was now operated upon as fol¬ lows : Iwo kilos of the ground bark were extracted first with cold, and then with hot alcohol. After distilling off the alcohol the liquid was poured into water, and the aqueous liquid filtered from the precipitated fatty matter and resin. The character of the latter bodies will be considered later. The aqueous liquid was treated with lead acetate for the re¬ moval of colouring matter, filtered, and the excess of lead removed by hydrogen sulphide. It was now found to be precipitated by all the usual alkaloidal reagents, and w'as subsequently evaporated to a thick syrup, and extracted in a Soxhlet with strong alcohol. To the dark coloured alcoholic solution a satu¬ rated alcoholic solution of mercuric chloride was added, which produced a whitish precipitate, soon changing, however, to a very dark, resin-like mass. After standing for a time, the clear liquid was decanted, and to the latter another portion of mercuric chloride was added, which produced a similar precipi¬ tate. lo the liquid decanted from the second precipitate a third portion of mercuric chloride was added, with the same result as before. The three precipitates (a), (6), and (c), after being washed with a little alcohol, were extracted with w-arm water, when in each case a considerable amount of a dark- coloured amorphous substance remained undissolved. The filtered liquids were all separately treated with hydrogen sul¬ phide to remove the mercury and again filtered. (a) This was a dark-coloured liquid, which was treated with animal charcoal, then made alkaline with sodium hydrate, and shaken out five times successively with hot amyl alcohol. The latter was then shaken with water, acidulated with hydrochloric acid, when dense white fumes were produced, probably due to ammonia. The acid liquid gave all the characteristic alkaloidal reactions, and, after treatment with animal charcoal, was tained nearly colourless. It was allowed to evaporate in a vacuous desiccator over potash and sulphuric acid, but, as it became concentrated, it acquired an ailmost black colour, showing that decomposition had ensued. It was, however, taken up , llttle ^solute alcohol, treated with animal charcoal, <id tihe solution precipitated by platinic chloride. 0-0360 gramme of this salt gave on ignition 0-0160 gramme of platinum or 44-4 per cent. Pt. The precipitate, therefore, consisted simply of ammonium-platinio chloride, which requires 43-9 nor cent. Pt. 1 Ihe liquid, after extraction with the hot amyl alcohol, when
    digitised image 1
    digitised image 2
    digitised image 3