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

  • Alexander Wynter Blyth
Date:
1909
Catalogue details

Licence: In copyright

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 / Alexander Wynter Blyth ... and Meredith Wynter Blyth. 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.

    62/680 (page 28)
    Microscopical observers rapidly multiplied as the instrument itself was perfected, and by about the year 1825, really good instruments, although not absolutely achromatic, could be purchased. In 1838, Ehrenberg brought out his great folio on Infusorial Life. The beauty of the illustrations in this have never been surpassed; they amply prove that very early in the nineteenth century, for those who could afford the expense, there were instruments of great power, precision, and definition.1 In 1844, Donne2 published his beautiful plates containing, among other things, some accurate representations of the milk corpuscles (see article on ‘ Milk ’). Dr. Ure, in an important case in which an attempt was made to evade the duty on cassava starch by calling it arrowroot, and importing it as such, detected the fraud by the microscopic appearances alone. An excellent collection of objects illustrating the minute anatomy of plants was to be found in 1845 in the Museum of the College of Surgeons, the catalogue of which was edited in an illustrated form by Professor Quekett.3 About the same time, Quekett also delivered several lectures on histology, in the course of which he pointed out the value of the microscope in the detection of fraud.4 § 31. In the latter part of the eighteenth and the beginning of the nineteenth century, chemistry advanced with rapid strides: Neumann Caspar5 made various experiments on milk, wine, butter, tea, coffee, and other substances; the Boerhaave School0 analysed milk; Berzelius issued his chemical papers; Scheele instituted a variety of researches, and thus the foundation was being laid of those processes which were improved and perfected by the philosophical mind of Liebig, and applied in the analyses of various vegetable products 7 by Mulder, many of whose methods are still quoted and taken to a certain extent as standard. This advance in chemical science was naturally accompanied by more elaborate and scientific works on food, and for the first time it became possible to study the subject in a philosophical manner, and to apply a variety of processes for the detection of fraud. microscope, by which an immense magnifying power was obtained. He afterwards published a work entitled, Micrographia; or, Movie Physiological Descriptions of Minute Bodies, made by means of Magnifying Glasses, with Observations and Enquiries thereupon, by R. Hooke, F.R.S. London, 1765. The work is a folio illustrated with well-executed copper plates. He describes and figures, like Leeuwenhoek, poppy seeds, vinegar eels, etc. He was a man of great ingenuity and celebrity. In a theoretical manner he anticipated the telephone, for in the preface he says: “ ’Tis not impossible to hear a whisper a furlong’s distance, it having been already done, and perhaps the nature of the thing would not make it more impossible though that furlong should be many times multiplied. ... I can assure the reader that I have, by the help of a distended wire, pro]legated the sound to a very considerable distance in an instant, or with as seemingly quick a motion as that of light, at least incomparably swifter than that which at the same time was propagated through the air, and this not only in a straight line, or direct, but in one bended in many angles. ” 1 Die Infusionsthierchen als vollcommene Organismen, by D. Christians Gottfreid Ehrenberg. Leipzig, 1838. 2 A. Donn6: Cours de Microscope. 3 Descriptive and Illustrated Catalogue of the Histological Series in the Museum of the Royal College of Surgeons, Vol. II., 1850. 4 Lectures on Histology, delivered at the Royal College of Surgeons, 1S50-1. 0 Neumann Casper, M.D., Vom Thee, Caffee, Bier und Wain. Lcipsic, 1735. The Chemical Works of Neumann Caspar, abridged and methodised, by William Lewis. London, 1773. 8 See chapter on ‘ Milk. ’ 7 The Chemistry of Animal and Vegetable Physiology, translated from the Dutch, by P. F. H. Fromberg. Edinburgh, 1845.