An experimental inquiry into the botanical history, chemical properties, and medicinal virtues, of the Spiræa tomentosa of Linnæus / by Elijah Mead.

  • Mead, Elijah.
Date:
1821
Catalogue details

Licence: Public Domain Mark

Credit: An experimental inquiry into the botanical history, chemical properties, and medicinal virtues, of the Spiræa tomentosa of Linnæus / by Elijah Mead. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    22/36 (page 16)
    The extract from the stalks has no superiority over that from the leaves, and as the quantity obtained from them is comparatively small, this preparation is considered as un- worthy of particular remark. In the leaves were found, in great abundance, the most active properties of the plant; they yielded to a watery decoction, a mild and pleasant bitter, and an active astrin- gent. If the decoction be evaporated, these principles are obtained in a solid extract, equal in weight to one-fifth of the leaves in a dried state. II. This experiment shows that the Spiraea yields its virtues but sparingly to Alcohol. The admixture of water with the several alcoholic tinctures, inducing no change, proves the absence of any resinous principle. III. The copious insoluble precipitate which took place, in this experiment, on the addition of Animal Gelatin, (a) demonstrates the presence of a large proportion of Tannin* From the brown precipitate with the Nitrate of Silver, (d) and the dark colour given by the Salts of Iron, (f) we in- fer the presence of the Gallic Acid, which appears in a combined state, as shown by the test /. A considerable portion of the extractive principle re- sides in the leaves, as indicated by the tests b and e. This plant appears to afford no Gum or Mucilage ; other- wise, they would have been pointed out by the tests i and k. IV. It appears, from this experiment, that all the proxi- mate principles of the Spiraea tomentosa are obtained by simple watery infusion, as proved by the several re-agents ; but though the comparative quantities of Tannin in the infusion and decoction were not particularly noticed, the probability is, that it is less in the former than in the latter, for the extract from the infusion was obviously more bitter and less astringent to the taste, than that pro- cured from the decoction. V. This experiment shows that the flowers and fruit are only valuable in common with other parts of the plant.