A contribution to the study of the blood and blood-pressure : founded on portions of the Croonian Lectures delivered before the Royal College of Physicians, 1896, with considerable extensions.

  • Oliver, George, 1841-1915.
Date:
1901
Catalogue details

Licence: In copyright

Credit: A contribution to the study of the blood and blood-pressure : founded on portions of the Croonian Lectures delivered before the Royal College of Physicians, 1896, with considerable extensions. 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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    means of a simple method to be subsequently ex- plained, the intervening units are read. Moreover, there exists another reason why each stage ought to be separately standardized, and why a mere gradation of the same colour is not only indefinite but is misleading, and that is the specific colour-curve of the blood else- where described (pp. 6, 7, 11 and 12). On setting up the standard.—To anyone who has not made an attempt of this kind it may seem an easy matter to prepare an imitation of the exact colour of a given percentage of normal blood in water, and thus to accomplish the first step towards the setting up of a haemoglobin standard. But a few trials will dispel such an impression, and will demonstrate the existence of a number of unforeseen difficulties which are in- separable from the task. The standardizing involves two steps, namely, (a) the adjustment of colour, and (b) the determination of the scale. (a). The adjustment of colour.—In the first instance, following others in the same line of work, experiments were made with carmine or carmine and picro-carmine in a glycero-gelatine basis. After much observation it was provisionally settled that the closest approximation to the colour of the blood solution was obtained by a combination of carmine, picro-carmine and hematoxy- lin; the blood and the standard solutions being ob- served by candle-light in cells having a background of opal glass. The gradations, of course, necessitated that the cells should be quite uniform in depth. After the lapse of some few weeks it was, however, obvious that