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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    catheter experiments. Such a possibility seems also to be suggested by some of the results obtained by Strassburg with lymph from the thoracic duct. Thus iu one experiment1 2 the quantity of lymph which passed through the aerotonometer was 29 c.c. The volume of oxygen contained in the aerotonometer at the beginning of the experiment was apparently about 054 c.c., and at the end 0'74c.c. Thus 29 c.c. of lymph had apparently given off ’20 c.c. of oxygen to the apparatus. As the coefficient of absorption of lymph for oxygen cannot well be higher than that of water (’024 at 37°) this experiment would seem to indicate that the oxygen tension of the lymph was at least 30 °/o °f an atmo- sphere. Such a high oxygen tension for lymph seems scarcely probable. Without entering into further criticisms we would venture to point out the need for further experimental control of these important investi- gations. Direct determinations of the arterial oxygen tension were first made by Herter* with the aerotonometer. He obtained only minimal values, the highest being 10 44 °/„ of an atmosphere. Tbe subject was again taken up some years ago by Bohr3, who devised for the purpose a much more perfect apparatus (the “ hoemat- aerometer”) through which ho was able to maintain during each experiment a constant and rapid stream of blood. He came to the unexpected conclusion that the oxygen tension may sometimes be slightly higher, and that the carbonic acid tension is often much lower in the arterial blood than in the alveolar air. From this he inferred that both absorption of oxygen and excretion of carbonic acid by the lungs are to a large extent active processes, and not due merely to diffusion. In a still more recent series of experiments Fredericq4 used an aerotonometer similar to Pfltiger’s original one, but so arranged that a continuous stream of blood trickled through the apparatus and back to the animal, as in Bohr’s experiments. Fredericq found that the oxygen tension of arterial blood is about 12 to 14°/0 of an atmosphere, and is always a little lower in the arterial blood than in the alveolar air. He criticises Bohr’s results on the ground that the latter did not present sufficient evidence that the gas tension in the blood and the air of the haemataerometer had equalised themselves. This criticism does 1 PflHger's Arcliiv, vit. p. 88. 2 Xeitsclirift fiir physiologische Chcmie, in. p. 98. 1879. 3 Ska nd. Arcliiv far Physiologic, 1891, p. 230. 4 Centralblatt fiir Physiologic, 1893, p. 33.
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