Fermentation and its bearings on the phenomena of disease : a discourse delivered in the City Hall, Glasgow, October 19th 1876 : under the auspices of the Glasgow Science Lectures Association / by John Tyndall.
- Tyndall, John, 1820-1893.
- Date:
- 1877
Licence: Public Domain Mark
Credit: Fermentation and its bearings on the phenomena of disease : a discourse delivered in the City Hall, Glasgow, October 19th 1876 : under the auspices of the Glasgow Science Lectures Association / by John Tyndall. Source: Wellcome Collection.
Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.
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![taneoiTsly from boot, or paste, or jam; its germs, whicli are abundant in the aii', liave been sown, and have germinated, ill as legal and legitimate a way as thistle-seeds Avafted by the wind to a proper soil. Let the minute spores of Penicilliutii be sown in a fermentable liquid, which has been previously so boiled as to kUl all other spores or seeds which it may contain; let pure air have free access to the mixture ; the Fenicillvmn will grow rapidly, striking long filaments into the liquid, and fructifying at its surface. Test the infusion at various stages of the plant's growth, you will never find ill it a trace of alcohol. But forcibly submerge the little ]ilant, push it down deep into the liquid, where the quantity of free oxygen that can reach it is insuflicient for its needs, it immediately begins to act as a ferment, supplying itself with oxygen by the decomposition of the sugar, and produc- ing alcohol as one of the residts of the decomposition. Many other low microscopic plants act iii a similar manner. In aei'ated liquids they flourish without any production of alco- hol, but cut off from free oxygen they act as ferments, pro- ducing alcohol exactly as the real alcoholic leaven produces it, only less copiously. For the right apprehension of all these facts we are indebted to Pasteur. In the cases hitherto considered, the fermentation is proved to be the invariable correlative of life, being produced l)y organisms foreign to the fermentable substance. But the substance itself may also have within it, to some extent, the motive power of fermentation. The yeast-plant, as we have learned, is an assemblage of living cells; but so at bottom, as shown by Schleiden and Schwann, arc all living organisms. Chenies, apples, peaches, pears, plums, and grapes, for ex- ample, arc composed of cells, each of which is a living unit. And hero I have to direct your attention to a point of ex- treme interest. In 1821 the celebrated French chemist Berard cstiililished the important fact tliat all ripening fruit, exposed to the free atmosphere, aljsorbed the oxygen of the atmosj)here, and liberated an approximately equal volume of carbonic acid. He also found tliat when ripe fruits were placed in a confined atmosphere, tlie oxygen of the atmo- sphere was first absorbed, and an equal volume of carbonic acid given out. But the process did not end here. After](https://iiif.wellcomecollection.org/image/b21450808_0015.jp2/full/800%2C/0/default.jpg)
