The oxygen tension of arterial blood / by John Haldane and J. Lorrain Smith.

  • John Scott Haldane
Date:
[1896]
Catalogue details

Licence: Public Domain Mark

Credit: The oxygen tension of arterial blood / by John Haldane and J. Lorrain Smith. 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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    In a control experiment, with no animal in the apparatus, the percentage loss was found to be exactly the same (2 8 °/0) as the average loss when an animal was present. Hence no carbonic oxide was oxidised in the body of the animal. The question has also been investigated by Martin1, whose experi- ments do not seem, however, to have been carried out by such an accurate method. He found that (in two experiments) there was a loss of 11 and 7'o°/0 of the carbonic oxide employed. This small loss may, however, have easily been due to an experimental error. To obtain independent evidence we made the following experiment. Carbonic oxide was breathed until the blood was 33 °/0 saturated. The subject was then made to breathe through a tin vessel containing potash lime into and out of a bladder, oxygen being at the same time supplied through a side tube in sufficient amount to prevent the bladder from collapsing. The saturation of the blood with carbonic oxide was now determined, and the determination repeated at intervals. As no appreciable quantity of carbonic oxide could escape through the lungs with this arrangement, any diminution in the saturation of the blood with carbonic oxide would indicate the occurrence of oxidation of carbonic oxide within the body. The results of the experiment were as follows: 3 minutes after beginning to breathe into bag. 10 50 1 hour n >> n >> )) >> n H n )> n Saturation of blood 33-3 °/„ 33-3 „ 33-3 „ 33-3 n IJ A sample of blood taken 35 minutes after the experiment ceased was 25 °/0 saturated. This experiment shows that within an hour there was no appreci- able disappearance of carbonic oxide from the body when escape through the lungs was prevented. Another similar experiment, in which, however, the blood was only lS'5°/0 saturated, gave exactly the same result. Oxidation, or disappearance in any other way, of the carbonic oxide present in the body, cannot therefore affect the accuracy of our method of determining the oxygen tension. 1 Comptes Reitdus, cxv. 835. 1892.