Variations experimentally produced in the specific gravity of the blood / by C.S. Sherrington and S. Monckton Copeman.

  • Sherrington, Charles Scott, Sir, 1857-1952.
Date:
[1893?]
Catalogue details

Licence: Public Domain Mark

Credit: Variations experimentally produced in the specific gravity of the blood / by C.S. Sherrington and S. Monckton Copeman. Source: Wellcome Collection.

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    SPECIFIC GRAVITY OF THE BLOOD. By C. S. SHERRINGTON, M.A., M.B., and S. MONCKTON COPE- MAN, M.A., M.D., late Research Scholar of the British Medical Association. Plate IV. From the Physiological Laboratory, St Thomas’s Hospital, London. The ingenious method devised by Roy1 for estimating the specific gravity of the blood puts into possession of the physiologist a means of making rapid and accurate observations at the expense of the with¬ drawal of a single drop, or even a fraction of a drop of blood. After a little experience of the method it seemed to us that it might be worth while to study in this way results which follow the injection of quantities of saline fluid into the circulation2. We are induced to place our observations on record here, although in some respects their extent is too limited, because circumstances render it unlikely that we shall have opportunity to further pursue the subject together. Roy’s method is now so well known that we need not explain it here in detail, except in so far as to refer to the particulars and pre¬ cautions followed in our own experiments. Briefly stated, his method consists in determining the specific gravity of the blood by observing whether a drop of it rapidly withdrawn from the circulation, and placed in a solution of known specific gravity, rises, sinks, or remains stationary in that solution. The first step in carrying out such observations is the preparation of the solutions which are to serve as standards of specific gravity. We prepared a series of solutions ranging from a specific gravity of 1025 to 1070, one member of the series corresponding to each unit of the third place of decimals. The solutions were prepared by weighing, and tested by an accurate hydrometer made by Dring and Fage. The solution employed was of Barff’s boroglyceride, glycerin and magnesium sulphate in distilled water with the addition of a small quantity of mercuric perchloride solution. From a solution of these with a sp. gr. of F040 the series of fluids was prepared by the addition of distilled water on the one hand or of glycerin on the other. 1 This Journal, Yol. v. p. ix. 2 Several of the results dealt with in the present paper were the subject of a short com¬ munication made to the Physiological Society in May 1890, cf. Proc. of the Phys. Soc. No. in. 1890.