Pasteur / by Percy Frankland ... and Mrs. Percy Frankland.

  • Percy F. Frankland
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Pasteur / by Percy Frankland ... and Mrs. Percy Frankland. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    who viewed the classical transformation of sugar into alcohol as a purely chemical process, depending not upon the living yeast cells which the microscope revealed, but upon the dead yeast undergoing ])ost- onortem decomposition. In Liebig's own words :— Beer yeast, and, in general, all animal and vegetable matters in putrefaction iuipart to other bodies the state of decomposition in which they are themselves. The movement which, by the disturbed equilibrium, is impressed on their own elements, is comnumicated also to the elements of bodies in contact with them. A few words of retrospect are necessary to show how these views of Liebig had gained ascendanc}^ Already in 177G, Spallanzani had shown that putrescible liquids and organic materials in general could be permanently protected from undergoing fermentation and decomposition by being thoroughly boiled and subsequently shielded from all access of air. Indeed, the well-known method of preserving the most varied food-stuffs, first turned to practical account by the ingenuity of the cook and confectioner Appert, and which has assumed such colossal dimen- sions at the present time, Avas the outcome of Spallan- zani's experiments. The results obtained by Spallan- zani were explained by Gay-Lussac as due to the exclusion of atmospheric oxygen from the substances employed. Gay-Lussac Avas led to this conclusion by an examination of Appert's contrivance for the pre- servation of animal and vegetable substances, which consisted in hermetically sealing them in vessels and subsequently submitting them to a high temperature in a water bath. He observed that a sample of grape- c 2
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