A critique of certain methods of gastric analysis / by David L. Edsall.

  • Edsall, David Linn, 1869-1945.
Date:
[1901]
Catalogue details

Licence: In copyright

Credit: A critique of certain methods of gastric analysis / by David L. Edsall. 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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    while it is not in Leo's method. Nevertheless con- clusions can be reached only by actual examination of the method. In using the procedure with solutions of Witte's peptone in HC1 of known strength, I obtained results which were practically absolutely accurate in every instance. The free HC1 in the mixture was determined by using phloroglucin-vanillin as an indi- cator and the combined HC1 by this method. The added results gave the total HC1; in almost every instance a quantity of HC1 practically equal to the amount known to be in the solution was shown by the method. The results, when lactic acid was present, were similarly accurate. Solutions of HC1, Witte's peptone, and of acid sodium and calcium phosphates were then tested, the phosphates being added in a strength of 0.2 per cent. Larger quantities of phos- phates are practically never found in the gastric con- tents. The results in all these instances indicated only the HC1 present and indicated that in full amount. The method is therefore apparently entirely accurate, certainly much more accurate than any other method which has been suggested with the possible exception of Sjoeqvist's; and it is so simple and so rapidly car- ried out that it is always at the service of the clinician. The method is as follows: The calcium phospho- tungstate is prepared by making a 4 per cent solution of commercial phosphotungstic acid, heating, and adding calcium carbonate until, after gentle boiling, the reaction becomes neutral; then filter. This solu- tion may be kept indefinitely. In carrying out the test determine the total acidity; then to ten cubic centimetres of gastric contents add thirty cubic cen- timetres of the calcium phosphotungstate solution, filter off the precipitate, wash the filter, collecting the washings with the filtrate, and titrate the filtrate and washings. Subtract the second result from the first, and the figures obtained represent the acidity due to