A treatise on therapeutics : comprising materia medica and toxicology, with especial reference to the application of the physiological action of drugs to clinical medicine / by H.C. Wood, jr.

  • Wood, H. C., Jr. (Horatio C.), 1841-1920.
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on therapeutics : comprising materia medica and toxicology, with especial reference to the application of the physiological action of drugs to clinical medicine / by H.C. Wood, jr. Source: Wellcome Collection.

    455/592
    parts of cold and in twenty-four parts of boiling water; is soluble in alcohol, fixed oil, and alkaline solutions. It is a feeble acid, but forms neutral salts with the alkalies. Benzoic acid is widely distributed through the vegetable kingdom, constituting the peculiar principle of all true balsams, and is occa- sionally present in the urine of grass-eating animals. It is a normal con- stituent of castor, and has been detected by Seligsohn ( Ghemische Centralblatt, 1861) in the suprarenal capsules of an ox. Benzoic acid is used considerably in the arts, and for this purpose is pre- pared from the allied hippuric acid of horse-urine, and also, it is said, from naphthalen. Physiological Action.—Locally applied, benzoic acid is a decided irri- tant, and its vapors, when inhaled, produce bronchial catarrh. Especial interest attaches to the elimination of benzoic acid, because, as was first discovered in dogs by Wohler, and afterwards in man by Ure, it appears in the urine, united with nitrogenous atoms, as hippuric acid. It becomes a matter of great interest to know where this change occurs; but this has not as yet been certainly determined. Kiihne and Hallwachs thought that the conversion occurred in the liver; but the more recent researches of Meissner and Shepard ( Untersuclivvgen iiher das EnMehen der Ei2iptirsaure in thierischen Organismus, Hanover, 1866) appear to show that it really takes place in the kidneys. Certainly it does not happen in the intestines or in the blood, since after the exhibition of large doses of benzoic acid it alone can be detected in the blood; and after the administration to rabbits by the mouth of large amounts of hippuric acid, only traces of the latter, with large quantities of benzoic acid, can be found in the blood, although the hii^puric acid reappears in the urine ; further, moderate amounts of hippuric acid injected into the blood cause severe symp- toms of poisoning, which is not true of benzoic acid. When very large amounts of benzoic acid are introduced into the blood, a portion escapes through the kidneys unchanged. According to Meissner and Shepard, some- times the benzoic acid is converted into succinic acid instead of hippuric acid in man, and in chickens it is habitually changed into two new products one of which is nitrogenous. ' The point as to whence the nitrogen necessary for the formation of the hippuric acid IS obtained has not yet been clearly made out. The testimony as to the effect of the ingestion of benzoic acid upon the urea and uric acid of the unne is singularly contradictory. Thus, Ure {Medico-CMn^rgical Tr^cuon.,..,,^ p 30, 1841), Leroy d'Etiolles (quoted by Stille), and Debouy (.p.oted by St.ll6) all affirm that the uric acid is very much dimin- shed or altogether absent, whilst Garrod {Manoirs of tU Chevucal Society, ^mTth t:i ^ 'T r^^^ ^^ Garrod tlZ! 7' ^'^ ^^^-^^^3^' whilst Keller and Meissner and fehepard (foe. cit.) declare that it is not affected. The only