The respiratory function of the blood.

  • Barcroft, Joseph, 1872-1947.
Date:
1914
Catalogue details

Licence: In copyright

Credit: The respiratory function of the blood. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    described, he made from the same solution, run from the same bui-ette, sixteen oxygen estimations. These were divided into four groups : the average of each group was taken, and the mean of tliese four averages was taken. The greatest error which entered into Peters' blood-gas analysis was doubtless in the measurement of 3 c.c. of fluid from an ordinary 50 c.c. burette, the meniscus in the case of haemoglobhi solution being none too well defined. This error, serious though it appears, is discounted by the fact that the 16 samples for analysis were run consecutively out of the burette. There may be a certain ruggedness in the individual figures, but the averages of the groups of four are very close to one another, since a positive error in one sample entails an equal negative error in the next: in the aggregate 48 c.c. used there is no appreciable error as compared with the 50 c.c. used for the iron analysis. Peters' figures for the oxygen of a single experiment are as follows: Oxygen in 3 c.c. of solution A in c.c. Group (1) ' ^ Group (2) Group (3) Group (4) •3667 -3667 '3576 -3527 •3449 -3374 -3640 •3510 •3482 ^3439 •3638 -3614 •3455 ■■dbVJ ^3455 -3537 Total 1-4053 1^3997 V4309 1^4188 Mean -3513 •3499 -3577 ^3547 Taking the average of these four means we get •3513 •3499 •3577 •3547 Total 1-4136 Mean -3534 c.c. Wlien it is remembered that the whole of these operations, both iron analyses and gas analyses, could be carried through successfuUy in a day, it will be clear what an advance Peters has made by the use of the modern technique both as regards the concordance of his figures and the certainty with which he has been able to put them forward. His figures for the volume of oxygen per gram of iron are as follows : Ox 394, 401, 399 Sheep 387, 384 Pig 388 Dog 384 Average 391