The bacteria of the stomach / by A. Lockhart Gillespie.

  • Gillespie Alexander Lockhart, 1865-1904.
Date:
[1892?]
Catalogue details

Licence: Public Domain Mark

Credit: The bacteria of the stomach / by A. Lockhart Gillespie. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    THE BACTERIA OF THE STOMACH.^ By A. Lockhart Gillespie, M.D., F.RC.P.EcL, Medical Registrar, Edinburgh Royal Infirmary. From the Research Laboratory of the Royal College of Physicians of Edinburgh. Two points have been constantly overlooked in the previous investi- gations into the growth of the organisms usually to be found in the human stomach before or after meals. The media in which they grow in this organ are generally acid, and this acid is known to exercise an inhibitory power over them. Hitherto it has been looked on as free hydrochloric acid, and the total acidity of the stomach contents has been regarded as due solely to free acid in estimating its power against micro-organisms. That any experiments, conducted by means of free HCl, and designed to show the bactericidal properties of this acid, are not applicable to the effect normally produced in the stomach by the total acidity present, is evident when the component constituents of that acidity, as shown by Hayem and Winter (^), Ewald (^), and myself 0, are considered. Instead of the free HCl being from ‘2 to •3 per cent., or equal to the total acidity, it is rarely, even in the latest stages of digestion, more than -05 per cent., or at most T per cent. The difference between these figures indicates the combined acidity,—the amount of hydrochloric acid combined with proteids, the proteid-hydro- chlorides as I have elsewhere (^) called them. These facts, then, modify the question very considerably. Another point, however, remains. If we take Maefadyen’s experiments (^) as a type, we find that he esti- mated the maximum antiseptic power of hydrochloric acid by means of gelatine plates, adding to their contents known quantities of HCl. What happened ? Some of the added acid combined with the proteids of the nutrient media, proteid-hydrochlorides were formed, and the deductions from the experiments were falsified. Again the acid was added in the maximum strength at the beginning of the experiments, and did not vary during them, a condition at variance with normal digestion. Macfadyen used well-known organisms — pathogenic and non-pathogenic—in his investigations, none of which, however, could be ^ Part of a Thesis for the degree of Doctor of Medicine, for which a gold inoda-l was awarded by the University of Edinburgh. ^2- /