A textbook of human physiology / translated from [the] 6th German edition by W. Stirling.

  • Landois, Leonard
Date:
1888
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Licence: Public Domain Mark

Credit: A textbook of human physiology / translated from [the] 6th German edition by W. Stirling. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    nearly all cases of aiuemia. Giant blood-corpuscles or macrocytes (10 n and more) are con- stant in ixinicious anaMiiia, and sometimes in leuka-mia, chlorosis, and liver cirrhosis {Gram). (3) Abnormal forms of the red corpuscles have been observed after severe burns {Lesser); the cor- puscles are much smaller, and under the influence of the heat, particles seem to be detached from them just as can be seen hai)pening under the microscope as the eti'ect of heat. Disintegration of the corpuscles into line droplets has been observed in various diseases, as in severe malarial fevers. The dark granules of a pigment closely related to h;ematin are derived from the granules arising from the disintegration of the blood-corpuscles, ami these particles float in the blood (nielansemia). This condition can be produced artificially by injecting bisulphide of carbon (7 to 70 of oil) suboutaneously into rabbits {ScIncalOc). They are partly absorbed by the colourless corpuscles, but they are also de[)osited in the spleen, liver, brain, and bone-marrow. (4) Sometimes the red corpuscles are abnormally soft, and readily yield to ])ressure. Parasites of Blood-Corpuscles.—Within the red blood-corpuscles of birds, flslies, and tortoises, parasites are occasionally developed in the form of round pseudo-vacuoles from which free parasites are subsequently discharged {Dtmilciusky). In malarial conditions in man, protozoon- like organisms have been seen within the red corpuscles, the plasmodium malariie {Mar- clUdfavd). The white corpuscles are enormously increased in number in leukaemia {J. H. Bennett, Virchotc). In some cases the blood looks as if it were mi.xed with milk. The colourless cor- puscles seem to be formed chiefly in bone-marrow {E. Neumann), and also in the spleen and lymphatic glands (myelogenic, splenic, and lymphatic leukremia). 11, CHEMICAL CONSTITUENTS OF THE RED BLOOD-CORPUSCLES.— (1) The colouring matter or hsemoglobin (Hb) is the cau.se of the red colour of blood ; it also occurs in muscle, and in traces in the fluid part of blood, but iu the last case only as the result of the solution of some red corpuscles. Its percentage composition is:—C 53-85, H 7-32, N 16-17, Fe 0-42, S 0-39, O 21-84 (dog). Its rational formula is unknown, but Preyer gives the empirical formula C,-,qq, Hq^q, Fe, So, Oj-,,. Although it is a colloid substance it crystallises in all classes lj of vertebrates, according to the rhombic system, and chiefly in rhombic plates or prisms; in the guinea-pig in rhombic tetrahedra ; in the squirrel, however, it yields hexagonal plates. The varying forms, perhaps, correspond to slight differences in the chemical composition in different cases. Crystals separate from the blood of all classes of vertebrata during the slow evaporation of lake- coloured blood, but with varying facility (fig. 13). The colouring matter crystallises very readily from the blood of man, dog, mouse, guinea-pig, rat, cat, hedgehog, horse, rabbit, birds, fishes ; with difficulty from that of the sheep, ox, and pig. Coloured crystals are not obtained from the blood of the frog. More rarely a crystal is formed from a single corpuscle enclosing the stroma. Crj'stals have been found near the nucleus of the large corpuscles of fishes, and in this class of vertebrates colourless crystals have been observed. Dichroism.—Haemoglobin crystals are doubly refractive and pleo-chromatic ; they are bluish- Ha;moglobin crystals from blood, a, I'ed with transmitted light, scarlet-red by reflected h, human ; c, cat; cl, guinea-pig; light. They contain from 3 to 9 per cent, water e, hamster; /, squirrel. of crystallisation, and are soluble in water, but more so in dilute alkalies. They are insoluble in alcohol, ether, chloroform, and fats. The solutions are dichroic : red in reflected light, and green in transmitted light. In the act of cry stall i.sation the hfemoglobin seems to undergo some internal change. Before it crystallises it does not diffuse like a true colloid, and it also rapidly decomposes hydric peroxide. If it be redissolved after crystallisation, it diffuses, although only to a small extent, but it no longer decomposes hydric peroxide, and is decolorised by it. [The presence of 6 favours crystallisation.] Fig. 13.
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