Volume 1

A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling.

Landois, L. (Leonard), 1837-1902. Lehrbuch der Physiologie des Menschen. English

Date:: 1891

Credit: A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling. Source: Wellcome Collection.

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$of blood be rapidly dried in a thin layer on a slide, the corpuscles retain their form and colour ; and if the process be done with sufficient rapidity, even the blood-platelets are retained. In investigating blood witli the microscope for forensic purposes, it is necessary to have a solvent for the blood when it occurs as stains on a garment or instrument. Dried stains are dissolved by a concentrated, or a 30 per cent., solution of caustic potash, or with one of the pre- serving fluids. If the stain be softened with concentrated tartaric acid, the colourless corpuscles are specially distinct (Struve). Nevertheless, corpuscles are often ')iot found in such stains. If the corpuscles have become very pale, their colour may be improved by adding a solution of iodide of potassium, a saturated solution of picric acid, 20 per cent, pyrogallic acid, or 3 per cent, solution of silver nitrate, 5. STROMA—LAKE-COLOURED BLOOD.—Many reagents cause the hemo- globin to separate from the stroma. The hseniogiol^in dissolves in the serum ; the blood becomes dark red and transparent, as it contains its colouring matter in solution, and hence it is called lake-coloured {Rollett). The aggregate condition of the hsemogiobin is not altered when the corpuscles are dissolved—it only changes its place, leaving the stroma and passing into the serum. Hence, the temperature of the blood is not lowered thereby. Methods.—To obtain a large quantity of the stroma for chemical purposes add 10 vols, of a solution of common salt (1 vol, concentrated solution and 15 to 20 vols, of water) to 1 vol. of defibrinated blood, when the stromata are thrown down as a whitish precipitate. For microscopical purposes mix blood with an equal volume of a concentrated solution of sodic sulphate, and cautiously add a 1 per cent, solution of tartaric acid. The following reagents cause a separation of the stroma from the haemoglobin, and thus make blood transparent :— {a) Physical Agents.—1. Heating the blood to 60° C. {Schultze) ; the temperature, however, varies for the blood of different animals. 2, Repeated freezing and thawing of the blood {Rollett). 3, Sparks from an S^^^ electrical machine (but not after the addition of salts to tlie v'^^^ blood) (7Zo/Ze;!0; the constant and induced currents (i\''cmrta7Ht), ß vJ / /2\/i (J) Chemically active Substances produced within the Body.— (j) i^Ju 4. Bile {Hilnefelcl) or bile salts {Plattner, v. Dusch). ^^-'^ 5. Serum of other species of animals {Landois); thus dog's A ) serum and frog's serum dissolve the blood-corpuscles of the y/ ''—cs^ rabbit in a few minutes. 6, The addition of lake-coloured ^ r^.. ^ ß blood of many species of animals {Landois). C^^> /j (c) Other Chemical Reagents,—7, Water, 8. The vapour of ^^^^ ^ chloroform {Böttcher) ; ether {v. Wittich) ; amyls, small -^j^, quantities of alcohol {Rollett) : thymol (Marchand) ; nitro-„ , , °' i ' c ^^ c benzol, paraldehyde, ethylic ether, aceton, petroleum ether, ^^^^^^jood-corpuscles of the frog &c, {L. Lewin). 9. Antimoniuretted hydrogen, arseniuretted ^^^^^ ° ^^P {^^tirting). hydrogen; carbon bisulphide; boracic acid (2 per cent.), added to the amphibian blood, causes the red mass (which also encloses the nucleus when such is present), the so-called zooid, to separate from the oecoid (fig. 9, d). Thezooid may shrink from the periphery of the corpuscle, or it may pass out of the corpuscle altogether (^rücfe) ; Brücke regards the stroma in a certain sense as a house, in which the remainder of the substance of the corpuscle, the chief part endowed with vital phenomena, lives. 11, Strong solutions of acids dissolve the cor- puscles ; more dilute solutions cause precipitates in the hsemoglobin. This is easily seen with carbolic acid {Hills and Landois, Stirling and Rannie). 12. Alkalies of moderate strength cause sudden solution. A 10 per cent, solution of potash placed at the edge of a cover- glass, shows the process of solution going on under the microscope. At first the corpuscles become globular, and so appear smaller, but afterwards they burst like soap-bubbles. 13. Such salt solutions, which in plants cause a separation of the protoplasm from the cell-mem- bi-ane (plasmolysis), make ox-blood lake-coloured, [14. NH4CI injected into the blood causes vacuolation of the red corpuscles {Bohritzky). 15. Sodic salicylate, benzoate, and colchicin dissolve the red corpuscles {N.Paton).] [Tannic Acid.—A freshly prepared solution of tannic acid has a remarkable effect on the coloured blood-corpuscles of man and animals—causing a separation of the haemoglobin from the stroma ( JV. Roberts). The usual effect is to produce one or more granular buds of hfemo- globin on the side of the corpuscles (fig, 9, h, c) ; more rarely the haemoglobin collects around the nucleus, if such be present (fig. 9, d), or is extruded, as shown in fig. 9, c] [Ammonium or Potassium Sulphocyanide removes the haemoglobin, and reveals a reticular structure—intra-miclear plexus of fibrils {Stirling and Rannie).'] [Syrup causes some of the red corpuscles to become twisted, and to exhibit redder patches in them (fig, 10).]$