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
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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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    germs of any kind have bad anj^tliing to do with his opera- tions. Still, when the fermented grape-juice is examined, the living Torula concerned in alcoholic fermentation never fails to make its appearance. How is this ? If no living germ has been introduced into the wine vat, whence comes the life so invariably developed there 1 You may be disposed to reply with Turpin and others, that in vii-tue of its own inherent powers, the grape-juice, when brought into contact with the vivifying atmospheric oxygen, rims spontaneously and of its own accord into these low forms of life. I have not the slightest objection to this explanation, provided proper evidence can be adduced in support of it. B\it the evidence addu.ced in its favour, as . far as I am acquainted with it, snaps asunder under the least strain of scientific criticism. It is, as far as I can see, the evidence of men, who, however keen and clever as' observers, are not rigidly trained exjjeritnenters. These alone are aware of the precautions necessary in investigations of this delicate kind. In reference, then, to the life of tho Avine vat, what is the decision of experiment when carried out by competent men 1 Let a quantity of the clear, filtered must of the grape be so boiled as to destroy such germs as it may have contracted from the air or otherwise. In contact Avith germless air the uncontaminated must never ferments. All the materials fo.r spontaneous generation are there, but so long as there is no seed sown there is wo life developed, and no sign of that fermentation which is tho concomitant of life. Nor need you resort to a boiled liquid. The grape is sealed by its own skin against contam- ination from without. By an ingcsnious device Pasteur has extracted from the interior of the grape its pure juice, and ]iroved that in contact with piu'c air it never acquii cs tho power to feiTQcnt itself, nor to produce fermentation in other liquids.* It is not, therefore, in the interior of the grape that the origin of the life observed in tho vat is to bo sought. * The liqnidg of tlio licaltliy animal body are also scaled fi'om external contamination. J'urc blood, lor exam])lc, drawn witli duo pieoaution.s from the veins, will never ferment or putrefy in contact with pure air.