A history of chemistry from the earliest times till the present day / by the late James Campbell Brown; with a portrait and one hundred and six illustrations.

  • James Campbell Brown
Date:
1913
Catalogue details

Licence: In copyright

Credit: A history of chemistry from the earliest times till the present day / by the late James Campbell Brown; with a portrait and one hundred and six illustrations. Source: Wellcome Collection.

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    and controversy remains. The qiiestion is still an open OTie, whether it is the action of the growth of the living cell, or a chemical substance incidental to cell growth, which is the true ferment, or whether both kinds—the living physiological and the dead chemical agent—have each its own separate and independent position, and are both true causes of fermentation. We recognise, as Dumas did, that no chemical substance ferments except in presence of water, and unless it is kept by means of the water in contact with some specific ferment. Alcohol in quantity will stop fermentation, and even small quantities of certain substances—sulphurous acid, carbon disulphide, phenol, corrosive sublimate, and others—have the same effect, more or less comjDletely. Perfectly pure grape sugar will not ferment, unless started by at least temjjorary contact with air, and Mitscherlich showed that while the liquid contents of a yeast ceil will convert cane sugar into glucose, the cell does not ferment the glucose into alcohol and (;arbon dioxide. Such, then, is the history of the development of opinion in regard to those processes of animal and vegetable ]:»hysiology. The history of the investigation of the composition and chemical attributes of animal and vegetable substances forms a part of the chemistry of the carbon compounds, H.c. 20
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