118 THE BLOOD AND ITS CIRCULATION. 



hematosine (a proteid substance, containing the coloring 

 matter of the globule). By injuring or destroying the glob- 

 ules we obtain first a solution of a bright red, which shortly 

 deposits crystals of different forms, varying in the case of 

 different animals. These crystals are red, generally irregular 

 in shape, and easily destroyed. They are crystals of hemo- 

 globin or hematocrystallin. Under the influence of different 

 reagents this substance develops new forms, such as haemin 

 and haematoidine, which crystallize into more regular forms 

 and with darker colors (Fig. 34, haemin crystals). Hematin 

 contains 7 per cent of iron, and as there are about 100 

 grammes of hematin in the entire mass of the blood, the 

 quantity of iron contained in the body would appear to be 

 about 7 or 8 grammes. 



Hemoglobuline becomes crystallized sometimes sponta- 

 neously, but more particularly when under the influence of 

 certain reactions or of certain physical actions, such as re- 

 peated freezing, followed by melting. In man it is then 

 precipitated under the form of prismatic crystals. In the 

 mouse and the guinea-pig the crystals are tetraedic, and 

 hexagonal, also, in the case of the squirrel. 



Hematin, on the contrary (or hematosine), which is the 

 coloring matter of the blood, properly so called (hemoglobin, 

 without the globulin), forms quite spontaneously in effusions 

 of blood in the tissues, and in blood kept for a long time in 

 a vessel : it is always amorphous, and appears as granulations 

 of a deep-red color. 



By combining hematine with an acid, hydrochloric acid, 

 .for instance, we obtain a new body, haemin (or chlorate of 

 hematine (Fig. 34), the crystals of which appear in the shape 

 of rhomboid plates, flattened at the corners, and of a deep 

 brown color. The crystals thus obtained are found only in 

 the blood. 



Hematoidine, finally, is derived from hematine, and is pro- 

 duced spontaneously in the system, particularly in old hem- 

 orrhagic spots, and generally in all effusions of blood. 



This substance, which appears in the form of small rhom- 

 boid and oblique crystals, is identical with the coloring 

 matter of the bile. Chemically considered, hematoidine is 

 not identical with hematine ; the difference is one part less 

 of iron and one more of water. 



These coloring matters of the blood, particularly the hem- 

 ato-cry stall in e, have been, during the last few years, the object 

 of very interesting researches, by means of their spectral 



