CHEMICAL CONSTITUENTS OF THE RED BLOOD-CORPUSCLES. 51 



undergo marked changes in form as the result even of slight extraneous influences. 

 With regard to lessened, resistance on the part of the erythrocytes, reference may 

 be made to p. 35. The nitrogen-content of the erythrocytes is diminished in 

 cases of secondary anemia, and it is increased in cases of pernicious anemia. In 

 the interior of the erythrocytes of birds, frogs, turtles, etc., low forms of animals 

 develop at times in the form of round pseudovacuoles, and out of which free 

 blood-worms subsequently develop. Also in cases of malarial infection in human 

 beings microbes of varying form (hemameba, Lavcran) have been observed within 

 the erythrocytes, and which probably are conveyed by stinging insects (mos- 

 quitos) in the same way as Texas fever is conveyed by ticks. They destroy 

 the red blood-corpuscles and in turn are destroyed by quinin. 



The white blood-corpuscles are generally increased 1 in all acute diseases in 

 which exudation takes place. They exhibit excessive increase in association 

 with so-called leukemia. In this disease the proportion of red to white blood- 

 corpuscles may be as 2 to i. In consequence, the blood acquires an appear- 

 ance as if it were mixed with milk. At the same time the number of 

 erythrocytes is diminished. Leukemia depends upon hyperplasia of the lymphoid 

 tissue or the bone-marrow. These causes are responsible for lymphatic and 

 myelogenous leukemia respectively. Lymphocytes and myelocytes are to be 

 carefully differentiated. The enlargement of the spleen is only secondary; there- 

 fore a pure variety of lienal leukemia is not accepted. Myelogenous leukemia 

 belongs probably among the active forms of leukocytosis. An active leukocytosis 

 is one that results through movement or migration of leukocytes into the blood- 

 current. This may involve the polynuclear neutrophile or eosinophile or the 

 mixed cells the latter with involvement of mononuclear elements containing 

 granules: myelemia. The passive form of leukocytosis comprises the various 

 forms of lymphemia. 



CHEMICAL CONSTITUENTS OF THE RED BLOOD-CORPUSCLES. 



The blood coloring-matter hemoglobin abbreviated Hb causes 

 the red color of the blood. It is found besides in muscular tissue 

 and in traces, probably only as a contamination through dissolved 

 cells, in the blood-plasma. In the spectroscope it exhibits an absorp- 

 tion-band in the green (Fig. 15, 4). Its percentage-composition ac- 

 cording to Hiifner is for the blood of swine, as compared with that for 

 the ox, in parentheses, C, 54.71 (54-66); H, 7.38 (7.25); N 17.43 

 (17.70); S, 0.479 (o-447); Fe, 0.399 (0.336); O, 19.602 (19.543). For 

 one atom of iron there are two atoms of sulphur in the horse, and three 

 in the dog. According to Hufner, the formula is C 6 3 6 H 1025 N 164 FeS 3 O 181 ) ; 

 the molecular weight is 14,129. Hemoglobin is soluble in water; when 

 heated it coagulates only with decomposition, retaining the sulphur 

 in firm union. Although it is a colloidal substance, it nevertheless 

 undergoes crystallization in all classes of vertebrates from which it has 

 thus far been obtained, in figures belonging to the rhombic system, 

 principally in rhombic plates or prisms, and from the guinea-pig in 

 rhombic tetrahedra. The squirrel, however, forms an exception, in- 

 asmuch as its crystals appear as hexagonal plates. The crystals 

 simply separate in all classes of vertebrate after slow evaporation of 

 blood rendered lake-colored, though with varying degrees of readiness. 



It is to be inferred that the variations in the form of the crystals in different 

 animals are dependent upon slight changes in chemical constitution. The hemo- 

 globin is readily crystallized from the blood of man, the dog, the mouse, the guinea- 

 pig, the rat, the marmot, the cat, the leech, the horse, the rabbit, birds, and rish; 

 and with difficulty from the blood of sheep, oxen, and swine; and not at all from 

 the blood of the frog. Rarely the hemoglobin of a single blood-corpuscle can be 

 seen to form a small crystal with inclusion of the stroma, as Landois also ob- 

 served in the case of rabbits' blood that had stood for a long time. Within the 

 large blood-corpuscles of fish the small crystal lies at times within the stroma 

 by the side of the nucleus. In this class of vertebrates colorless crystals also have 

 at times been observed. 



