The preparations of conium maculatum of the British pharmacopoeia, 1864 / by John Harley.

  • Harley, John, 1833-1921
Date:
1867
Catalogue details

Licence: Public Domain Mark

Credit: The preparations of conium maculatum of the British pharmacopoeia, 1864 / by John Harley. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    midsummer 1868 (an exceptionally hot and dry season). The roughly-ground dried leaves were exhausted by percolation of proof spirit. The spirit was then distilled off, and the extract fur- ther evaporated until one fluid drachm equalled one drachm of the dried leaves — £ ounce of fresh herb. It is a dark yellowish brown watery fluid of a rank hemlock odour, depositing much greenish brown resin on the sides of the bottle. 1,000 grain measures yield 195 grains of brig]it orange brown brittle extract, which rapidly absorbs water to the extent of 19 per cent. 9. Benzoate of Gonia.—A member of a city firm of druggists lately deposited with me a solution labelled “ Benzoate of conia: one drachm contains 2 grains ; dose from 5 to 20 drops.” I subsequently received from him samples of the solid sub- stance. A dry salt of conia is a great desideratum, and I welcomed the preparation as a valuable addition to our Materia Medica. Failing, however, to find any mention of benzoate of conia in chemical works, and finding that I could not obtain any physiological effects in my own person and in others, even •when the dose was increased to 20 grains of the solid substance, I was induced to give it a thorough examination. The solution is a spirituous, bright, straw-coloured fluid, of sp. gr. 'OOFS, neutral, but of a warm sodaic taste ; 1,000 grain measures yield 29'5 grains of residue identical with the solid substance. The mineral acids immediately, and acetic acid after an interval, precipitated abundance of benzoic acid. No conia odour was developed when either the solution itself or the acid fluids from which the benzoic acid had been precipitated, were supersatu- rated with potash. The solid is composed of granular masses of minute crystals of a dirty-straw colour, readily soluble in dilute spirit, and soluble, with slight effervescence, discoloration, and liberation of hydrochloric acid gas, in sulphuric acid. Neither heat nor excess of potash elicits the faintest odour of conia. At a high temperature it melts and blackens, emitting white fumes of benzoic acid, then boils and burns with a bright but smoky flame. After complete combustion 100 grains yield 47‘2 grains of ash, which dissolves in dilute nitric acid, with brisk and pro- longed effervescence; it is chiefly composed of soda, with some chloride of sodium, a little magnesia, and a trace of sulphuric acid. The reactions are in the main those of benzoate of soda;