Examination of the blood : with examples of the wide range of its value / by Herbert French.

  • French, Herbert Stanley, 1875-1951.
Date:
1903
Catalogue details

Licence: In copyright

Credit: Examination of the blood : with examples of the wide range of its value / by Herbert French. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    be poured off, and the vessel filled with fresh. It should then be stoppered, and the slips are ready for use. When one is needed, it is taken out with forceps ; the alcohol is burned off in the flame of a spirit-lamp, and the glass is left quite clean and dry. Should it splinter in the flame, it means that the alcohol is not quite absolute,” and the splintering ceases if that in the jar be poured off and fresh pure alcohol poured in. The lobule of the ear is the best place from which to procure blood for an examination. The lobule is sometimes cleaned with ether first; but warm water is as good, and then the ear should be carefully dried. Holding the lobule firmly at its base, between two fingers of the left hand, a quick deep stab is made with the needle, and the patient feels a very trifling pain ; this pain is made less obvious when the lobule is firmly held by the operator’s left hand. The first drop of blood is wiped off, and the next may be used either for a film, or for counting corpuscles, or for haemoglobin-estimation, or for determination of specific gravity; and successive drops may be used for all four. An excellent way of making a film is by means of a cigarette-paper. The latter is cut just narrower than the cover- slip ; a drop of blood is touched with one end, being lightly smeared along a thin line at the machine-cut edge of the paper ; the blood-smeared end is then laid, smeared surface downwards, upon one end of a cover-slip, and the cigarette- paper drawn quickly and steadily along the surface of the glass. A little practice will ensure the making of smooth, even films, and their thickness may be varied by varying the angle at which the cigarette-paper meets the cover-slip. The blood should dry upon the glass almost as quickly as the paper is drawn along; otherwise the corpuscles run together in rouleaux. The film having been made, the question arises as to how best to stain it. Many observers prefer Jenner’s stain, because it both fixes and stains at the same time, and in a few minutes. Others prefer fixing the film by dry heat at 120° C. for two hours, and then staining with methylene blue and eosine. For differential counts some prefer Phear’s stain, which is put upon the lobule of the ear ; the ear is then pricked through it, and a drop of mixed blood and stain examined