On continuous molecular changes, more particularly in their relation to epidemic diseases : being the oration delivered at the 80th anniversary of the Medical Society of London / by John Snow.

  • Snow, John, 1813-1858.
Date:
1853
Catalogue details

Licence: Public Domain Mark

Credit: On continuous molecular changes, more particularly in their relation to epidemic diseases : being the oration delivered at the 80th anniversary of the Medical Society of London / by John Snow. 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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    vital process, and the production of alcohol and car- bonic acid a chemical process inseparable from it. According to this view, whilst cell development is un- doubtedly a vital process,* digestion and the formation of compounds to be secreted or excreted are chemical processes. There is no objection to such a distribution of terms, but it must be remembered that the decom- position of sugar into alcohol and carbonic acid is as closely connected with a process of organization as are the sensibility and contractility of animal tissues. This blending together of what we call vital and what we necessary to tte chemical activity of tlie mucus, there originates, without as it appears the influence of a living plant, a process, of cell-formation (the origiu of the so-caUed fermentation fungus), and it appears that it is only the vegetation of these cells which produces the peculiar changes that occur in the fluid. * Schleiden, however, speaking of vegetable cells, says,— If further we regard the easy transformation of the assimilated matters, and may, from artificially conducted experiments, draw the conclusion that the nitrogenous matter which I have called mucus, and which forms the cytoblast, is the substance which calls forth these transformations; and if we further remark that sugar and dextrine are more easily soluble than jelly, and that sugar and gum are changed into jeUy, if the quantity of water is not increased, and which must be necessarily precipitated, we must regard the whole process of cell-formation as simply a chemical act. The gathering together of granules of mucus to form a cytoblast we cm as little explain as that, when we form a solution of two salts, if we throw into the mixture a crystal of one or other salt, that salt alone crystallizes around it.— Opus cit. p. 35.