Antiseptic surgery : its principles, practice, history and results / by W. Watson Cheyne.

  • Cheyne, William Watson, Sir, 1852-1932.
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: Antiseptic surgery : its principles, practice, history and results / by W. Watson Cheyne. Source: Wellcome Collection.

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    he also succeeded if he subjected the milk to prolonged boiling at 100° C. Such milk remains unaltered for an indefinite length of time, but it readily decomposes if unheated dust be introduced into it in the manner to be afterwards described. The most striking of Pasteur's experiments is that of the flask with the bent neck. A flask containing, say, yeast water is heated so as to render its contents pure. Its neck is drawn out and bent, and then, after boiling, the lamp is simply with- Fig. 3.—Pasteur's flask with the bent neck. (From Pasteur.) drawn, the neck being neither heated, sealed, nor plugged (Fig. 3). Nevertheless the fluid does not undergo any change. If, on the other hand, the neck of this flask be sealed during ebullition, a more or less perfect vacuum is thus pro- duced, and then, if the neck be broken after cooling, au- rushes violently into the flask, carrying with it its dust. The result is that fermentative changes occur in the fluid. In the same way, if one of the flasks with open necks, the contents of which have remained for some time j)ure, has the neck broken off short, the fluid in its interior rapidly undergoes fermenta- tion ; or again, if the neck be not bent but be kept straight, so as to allow dust to fall in, fermentation rapidly occurs. The explanation of these results is that in the case of the flask with the long neck the dust is caught in the curve, which in the first inrush of air is filled with water, which filters the air (Mr. Lister's view). Pasteur had supposed that part of the air dust entered the vessel instantly, but that the fluid and the walls of the flask were at that time so hot that any living particles present were immediately destroyed. As will be seen f\u-ther on, Pasteur also found that it was I