Foods, their composition and analysis : a manual for the use of analytical chemists and others : with an introductory essay on the history of adulteration / by Alexander Wynter Blyth.

Date:
1882
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Licence: Public Domain Mark

Credit: Foods, their composition and analysis : a manual for the use of analytical chemists and others : with an introductory essay on the history of adulteration / by Alexander Wynter Blyth. Source: Wellcome Collection.

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

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    betical. He paid mucli attention to the composition of diseased ; milk; and although he made little, if any, use of the microscope, the chemical details of the work are superior to any that had hitherto appeared (see article on “Milk”). § 34. About the same time, after more than twenty years had elapsed since the publication of any English work—Accum’s being the last—the subject of adulteration was revived here by John Mitchell,* who published what must be considered a very useful volume, although many of the tests he gives would scarcely stand the ordeal of a court of justice at the present day. He states, e.g., that if an infusion of tea, treated with sulphate of copper, and heated, throws down a copious chocolate precipi- tate, “hawthorn is present; if the infusion becomes of a bright green colour on adding caustic soda, sloe leaft is probable; but if, on the addition of acetic acid, the solution possesses a very bright colour, “its presence is certain.” Mr Mitchell’s confidence in these reactions is amusing ; but, on the other hand, the greater number of his observations are still valid. § 35. In 1850 Chevallier issued his dictionary of adulteration,]; which, through successive editions, has from the time of its ap- pearance been, par excellence, the standard French work on the subject. Many years before the publication of his great work, however, M. Chevallier had practically studied the question, as is proved by documentary evidence, and by his numerous repre- sentations to the government on the necessity of amending the law. In a petition presented to the National Assembly in 1848, he says §—“Since 1833 I have constantly addressed to the Chambers of Deputies petitions on the same subject, but these petitions have ever been abortive, and fraud has progressively augmented.” The first edition of his dictionary, written in a clear style, contained an excellent resume of what was already known with regard to falsifications, and, besides, was enriched with many new facts—the result of a long experience. In the same year, 1850, Alphonse Normandy, who published the “Treatise on the Falsifications of Food, with the Chemical Means em- ployed to detect them.” By John Mitchell, F.C.S. London, 1848. t The belief in the adulteration of tea by the leaves of the sloe is almost contemporaneous with the introduction of tea itself into England, and there are numerous allusions to the practice scattered throughout the various fugitive contributions to literature. However, that tea has been actually adulterated with sloe leaves rests on no direct evidence worthy of consideration. t Dictionnaire de.s alterations et clesfalsifications des substances alimentaires. 'V' A- Chevallier. Paris, 1st ed., 1850. b Petition sur Its falsifications, adressae a Vassemblee Rationale. Far A. Chevallier. 1848.