The chemistry of cookery / by W. Mattieu Williams.

  • Williams, W. Mattieu (William Mattieu), 1820-1892.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: The chemistry of cookery / by W. Mattieu Williams. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    of liquid, and then placed on a sheet of white paper to serve as a standard. A second slip of the test-paper is then steeped in the suspected wine in the same manner, and laid beside the former. It is asserted that 1-100,000 of magenta is sufficient to give the paper a violet shade, whilst a larger quantity produces a carmine red. With genuine red wine the colour produced is a greyish blue, which becomes lead-coloured on drying.’ I copy the above from the ‘ Quarterly Journal of Science ’ of April 1877. The editor adds that the inventors of this paper have discovered a method of removing the magenta from wines without injuring their quality, ‘ a fact of some importance, if it be true that several hun- dred thousand hectolitres of wine sophisticated with magenta are in the hands of the wine-merchants ’ (a hectolitre is = 22 gallons). Another simple test that was recommended at the time was to immerse a small wisp of raw silk * in the suspected wine, keeping it there at a boiling heat for a few minutes. Aniline colours dye the silk permanently ; the natural colour of the grape is easily washed out. I find on referring to the ‘Chemical News,’ the ‘Journal of the Chemical Society,’ the ‘ Comptes Rendus,’ and other scientific periodicals of the period of the phylloxera plague, such a multitude of methods for testing false colouring materials that I give up in despair my original intention of describing them in detail. It would demand far more space than the subject deserves. I will, how- ever, just name a few of the more harmless colouring adulterants that are stated to have been used, and for ' In repeating these experiments I find that the best form of silk is that which the Coventry dyers technically call ‘boiled silk,’ i.e. raw silk boiled in potash to remove its lesinous varnish. In this slate the aniline dyes attach themselves to the fibre very readily and firmly.