Observations on the combination of acids, bitters, and astringents : being a refutation of some of the principles, contained in Dr. Percival's essay, on bitters and astringents / by James Woodhouse, M.D.

  • Woodhouse, James, 1770-1809.
Date:
MDCCXCIII [1793]
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the combination of acids, bitters, and astringents : being a refutation of some of the principles, contained in Dr. Percival's essay, on bitters and astringents / by James Woodhouse, M.D. 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.)

    20/24
    i. Acids and bitters do not neutralife each other. i. Acids by a fuperior affinity to the bafe of the aftringent principle, by detaching the gallic acid, decompofe, but do not neutralife aftringents, forming falls or Jaline gums of different degrees of aftringency, according to the acids employed.* The aftringency of the oak bark was increafed by the vitriolic acid, becaufe it contains a large proportion of earth unfaturated by the gallic acid, hence the copious precipitation, upon the addi- tion of the alkali, after adding the vitriolic acid. By fpontaneous evaporation in the open air, an acid fait is produced, and during the chryftallizati- on, micaceous fpangles, refembling drops of tar thrown into water, appear fwimming on the fur- face of the fluid. Th e bark of an oak tree may be confidered as a coat of pure argillacious earth j to prove this, let * The diftilled acid of fugar, the acids of ci- trons; forrel and phofphorus, and the acid of tartar, which appears to be a modification of the gallic acid, form gams with the earth of alum. Vid. Keir's chemical dictionary*