COMPOSITION OF REMATIN. 119 



Ultimate Analysis of flcematin. 



Carbon C53.47 



Hydrogen 54.45 



Nitrogen 103.9G 



Oxygen 118.81 



Iron 69.31 



1000.00 



The remarkable feature in the composition of this "body is the large 

 quantity of iron it contains. The percentage amount of this i ron in the 

 metal in the blood of the foetus is much greater than in that of cells - 

 the mother. After birth the proportion declines, but it rises again at 

 puberty. These variations in the amount of the iron are, however, de- 

 pendent on corresponding variations in the amount of cells. 



The importance of the remark, when we arrive at the study of the 

 bile, justifies us in repeating that the iron of the blood belongs to the 

 haematin of the cells, its percentage proportion varying with their condi- 

 tion, and also with the region of the circulation from which they have 

 been drawn. As derived from different animals, the cells present differ- 

 ent quantities of this metal. Thus Schmidt found in 100 parts of dry 

 blood-cells in man, 0.4348 ; in the ox, 0.509 ; in the pig, 0.448 ; and in 

 the hen, 0.329. 



The crystalline substance of blood occurs under three dmercnt forms, 

 in prisms, tetrahedra, and hexagonal tablets. In the pris- Cr stalline 

 matic form it is derived from human blood, that of fishes, substance of 

 and of some mammals ; in the tetrahedral form it is obtained blood ' 



Fin. 4i. 



Fig. 48. 



Human bK>ou-c;-ystals. 



Blood-crystals o:' Guinea-pig. 



from Guinea-pigs, rats, and mice; in the hexagonal' form, from squir- 

 rels. Blood-crystals are of a red color, without smell or taste, losing 

 their water of crystallization under exposure to the air, the different forms 

 presenting different rates of solubility ; the tetrahedral being soluble 



