The relative volume or weight of corpuscles and plasma in blood / by G.N. Stewart.

  • Stewart, G. N. (George Neil), 1860-1930.
Date:
[1899?]
Catalogue details

Licence: Public Domain Mark

Credit: The relative volume or weight of corpuscles and plasma in blood / by G.N. Stewart. Source: Wellcome Collection.

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    is approximately correct for a wide range in the relative proportion of corpuscles and serum in dog’s blood. It gives results which agree most closely with the results of the colorimetric method and of Hoppe- Seyler’s method when the percentage of serum is such as is found in normal blood. The agreement is less close for artificial mixtures of corpuscles and serum in which the percentage of serum is higher than the maximum or lower than the minimum percentage found in normal blood, the formula giving too low a value in the latter case, and, in general, somewhat too high a value in the former. A somewhat simpler, but, on the whole, a less accurate formula is p = ~ —^(6)-~ (cited as formula (2)). A's For a first approximation the factor 174*5 can become 174. When the percentage of serum is low this formula gives somewhat lower values than the other, and somewhat higher values when the percentage of serum is high. In both formulae the conductivities are to be expressed in reciprocal ohms at 50° C. multiplied by 108. Bugarsky and Tangl’s formula gives considerably lower results, in general, than either of my formulae, and results that are doubtless too low. The observations from which formulae (1) and (2) are deduced consist, (1) of measurements of the conductivity of the serum and entire blood in normal defibrinated blood in which the proportion of corpuscles of serum was also deter¬ mined by the colorimetric method, or by Hoppe-Seyler’s method, or by both. (2) Of measurements of the conductivity of the serum and entire blood in artificial mixtures of corpuscles and serum made by diluting the sediments obtained by centrifugalising defibrinated blood, with known quantities of its own serum. The proportion of corpuscles to serum in the original sediment was determined by the colorimetric method or by Hoppe-Seyler’s, or by both. The following experiments illustrate the relation between the electrical conductivity of the serum and blood in sediments diluted with serum and the quantity of serum found by other methods. In all the experiments a weighed or measured quantity of the sediment was taken, and to it was added a weighed or measured quantity of the serum of the same blood, obtained either from the clot or from the defibrinated blood by centrifugalisation. The pipettes used for measuring the blood were all corrected by determining the weight of the distilled water needed to fill them to the mark. When the serum