INORGANIC COMPOUNDS, 



77 



Sodium and potassium salts. Probably 200 grins, may be taken 

 as an average amount of sodium chloride (common salt) in the adult 

 human body. It is a most important food, and about 16 grms. are 

 daily excreted in the urine, 1 and smaller amounts in the sweat and 

 faeces. If potassium chloride be substituted in the food for the sodium 

 salt, disturbances arise from deficiency of the latter. The tissues, how- 

 ever, retain common salt very tenaciously, so that during a dietary 

 devoid of salt it disappears slowly from the urine. 



During its passage through the body, it facilitates the absorption of 

 proteid food, and increases tissue metabolism. The following table 2 gives 

 the probable relative amounts of sodium and potassium chlorides in 

 parts per thousand : 



Blood 



Blood corpuscles 



Plasma 



Lymph 



Chyle 



Pancreatic juice 

 (from perman- 

 ent fistula) 



2-50 0-93 



Bunge found that the soda salts are more abundant in embryonic 



1 Vierordt's " Daten u. Tabellen," 1893, Aufl. 2, S. 122. 



2 From M'Kendrick's "Text-book of Physiology, " Glasgow, 1888, vol. i. p. 39. 



