110 ESSENTIALS OF CHEMICAL PHYSIOLOGY 



Lesson IV. Both serum globulin and serum albumin probably con- 

 sist of more than one protein substance (see Lesson XX.). 



Fibrin ferment. Schmidt's method of preparing it is to take serum 

 and add. excess of alcohol. This precipitates all the proteins, fibrin 

 ferment included. After some weeks the alcohol is poured off ; the 

 serum globulin and serum albumin have been by this means rendered 

 insoluble in water ; an aqueous extract is, however, found to contain 

 fibrin ferment, which is not so easily coagulated by alcohol as 

 the other proteins are. A simpler method of preparing fibrin 

 ferment in an impure but efficient form is given in the footnote 

 on p. 101. 



B. Extractives, These are non-nitrogenous and nitrogenous. The 

 non-nitrogenous are sugar (0'12 per cent.), fats, soaps, cholesterin ; and 

 the nitrogenous are urea (0'02 to 0'04 per cent.), and still smaller 

 quantities of uric acid, creatine, creatinine, xanthine, and hypoxan- 

 thine. 



C. Salts, The most abundant salt is sodium chloride : it con- 

 stitutes between 60 and 90 per cent, of the total mineral matter. 

 Potassium chloride is present in much smaller amount. It consti- 

 tutes about 4 per cent, of the total ash. The other salts are phos- 

 phates and sulphates. 



Schmidt gives the following table : 



1,000 parts of plasma yield 



Mineral matter . . . . . . 8-550 



Chlorine 3'640 



S0 3 0-115 



P 2 O 5 0-191 



Potassium 0-323 



Sodium 3-341 



Calcium phosphate 0-311 



Magnesium phosphate 0-222 



THE WHITE BLOOD CORPUSCLES 



These corpuscles are typical animal cells. Their nucleus consists 

 of nuclein ; their cell-protoplasm yields proteins belonging to the 

 nucleo-protein and globulin groups. The protoplasm of these cells 

 often contains small quantities of fat and glycogen. 



THE RED BLOOD CORPUSCLES 



The red blood corpuscles are much more numerous than the white, 

 averaging in man 5,000,000 per cubic millimetre, or 400 to 500 red to 

 each white corpuscle. The method of enumeration of the corpuscles 

 is described in the Appendix. 



