An investigation of the properties of Bignonia catalpa of Linnaeus / by Robert Holmes.

  • Holmes, Robert.
Date:
1803
Catalogue details

Licence: Public Domain Mark

Credit: An investigation of the properties of Bignonia catalpa of Linnaeus / by Robert Holmes. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    eel, until it was reduced to half the quantity. The liquor was of a brown colour, intensely bitter, and somewhat astringent to the taste; possessing an un- pleasant aromatic smell. It produced a black co- lour, with the solution of iron, and changed the tinc- ture of litmus to a red. Analysis. Four pints of this decoction afforded by evaporation, six drams and two scruples of a dark brown gummi-resinous extract. To four drams of this extract, four ounces of alcohol were added. It took up nearly three scruples ; the spirit was bitter and of a brown colour. I then added to this spirit- ous solution nearly six times its quantity of distilled water, and in a short time a precipitation was gradu- ally effected, with a flaky appearance, inclining rather to a brown colour. This being separated by the fil- ter and dried, weighed eighteen grains. A portion of this resin was re-dissolved, to which I added the nitrate of silver. A white colour was pro- duced, succeeded by a precipitation, which was inso- luble in water. From this circumstance I concluded that the solution contained muriatic acid. The fluid which passed the filter was evaporated. During which process a curd-like substance was seen floating near the bottom of the vessel, but too small in quantity to induce me to filter a second time. The eva- poration being accomplished, I obtained nine scruples of a gummi-mucus substance. Equal portions of which I put into four wine glasses, to which I added equal quantities of water, and as soon as a solution was ef- fected, I treated them as follows :