An endeavour should be made to obtain a solution for microscopical, chemical, and spectroscopical examination. The solvent, in order to obtain the blood corpuscles in as natural a form as possible, should approach in its specific gravity the liquor sanguinis.
The following solvents fulfil this purpose:
(a) Glycerine and water, 1 to 7 (sp. gr. 1030).
(b) Pacini‘s solution of chloral hydrate in water (1 in 10).
(c) Normal saline solution.
(d) Roussin‘s solution of glycerine 3 parts, sulphuric acid 1 part (by weight), and water so that the mixture shall have a sp. gr. of 1028.
(e) Saturated solution of borax in distilled water.
If distilled water alone be used, the red corpuscles lose their hæmoglobin and become “laked” or “phantom” corpuscles; if the solution be of higher sp. gr. than liquor sanguinis, then the corpuscles become crenated and irregular in shape.
Fig. 5.—Photo-micrograph of flax fibres, × 250.
(R. J. M. Buchanan.)