164 CIRCULATING FLUIDS: 



white. In all of them there is cholesterin^ margaric and oleic 

 acids. Berzelius could detect no phosphorus in the fat of fibrin ; 

 neither did Lecanu find any in the fat of the serum. The fat 

 containing phosphorus, which Boudet found in the blood, must 

 belong to the corpuscles. We cannot form any veiy clear idea of 

 the manner in which these metamorphoses are conducted ; it is, 

 however, probable that the phosphorized fats are conducted to 

 the brain. Since the fats that are taken as food consist, for 

 the most part, of stearin, margarin, and olein, it would appear 

 as if fatty acids were formed from them by a process of oxyda- 

 tion during the succeeding formation of blood-corpuscles, and 

 the consumption of l\Tnph-, chyle-, and oil-globules. 



The elementary composition of many of the substances that 

 are formed from the blood, and of some that occur in it, are 

 known to us, but of the greater number of the matters that are 

 produced during its metamorphosis, jjarticularly of the extrac- 

 tive matters, we are entirely ignorant. 



The extremely high atomic numbers of many of these sub- 

 stances, as, for instance, of the protein-compounds, renders it 

 very probable that each atom is decomposed into various new 

 atoms of less atomic weight. We are, however, at present en- 

 tirely deficient in many of the requisite data, in our knowledge 

 regarding the connecting links, as, for instance, of the compo- 

 sition of the extractive matters, of the difterent tissues, &c., 

 without which even a superficial insight into the nature of the 

 metamorphosis of the blood cannot possibly be obtained. 



With the scanty materials in our possession, we may never- 

 theless attempt an ideal sketch of the metamorphic action that 

 goes on in the blood, the conditions being that there is an 

 absorption of oxygen, and that carbon is given off; it will, at 

 any rate, afi'ord an illustration of the facility with which such 

 equations may be deduced, and of the slight degree of confi- 

 dence that should be placed on their interpretation, unless they 

 are tested by established facts. 



We may, for instance, suppose that 4 equiv. of the organic 

 portion of htcmatin (C^^ H,^„ Ng Og), by the absorption of oxygen, 

 will be decomposed into choleic acid, uric acid, urea, and car- 

 bonic acid. Thus — 



4 At. Haematin . . C^e Hga N,2 0., T _ it at n 



p. r ^176 "88 -^'12 "188 



^164 J 



164 At. Oxygen 



