A course of elementary practical physiology and histology / by M. Foster and J.N. Langley.

  • Foster, M. (Michael), Sir, 1836-1907.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: A course of elementary practical physiology and histology / by M. Foster and J.N. Langley. Source: Wellcome Collection.

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    17. Let a drop of fresh blood of a frog or newt drop into 5 c.c. of a mixture containing 0'6 p.c. NaCl, 0*6 p.c. peptone, 0*02 p.c. methyl-violet; and stir at once. In this fluid the platelets are preserved for a day or so. The nuclei of all the elements of the blood are stained rather deeply; the cell substance of the white corpuscles and of the platelets takes a light stain (cp. 3, § 5). 18. The platelets and other corpuscles of the blood may also be preserved by allowing a drop of blood to run into 5 c.c. of (1) a mixture containing 0*5 p.c. osmic acid, and 0*75 p.c. NaCl., (2) 1 p.c. oxalate of potassium. In the former fluid they do not stick together, and to a slight extent only in the latter. Permanent preparations may be made from the blood mixed with osmic acid. The mixture is allowed to stand for a day; the fluid decanted, water is added to the residue and shaken; when the cor- puscles have settled, the water is poured off; the process is repeated; 50 p.c. alcohol is then added, in this the corpuscles can be kept till required; with a little care the corpuscles can be stained. B. Corpuscles of Man. 1. With a sharp needle1 prick the finger a few millimetres from the root of the nail; touch with the centre of a cover-slip the drop of blood which issues ; lower the cover-slip on a slide (cp. A. § 1). Observe the red corpuscles. a. They roll about readily when the cover-slip is lightly touched. Soon after being taken from the body they stick to one another, and, owing to their shape, usually in rouleaux. 1 It is better to use the triangular needle specially made for the purpose.