THE BLOOD AND THE LYMPH 259 



of leukocytes decreased by 90 per cent., but the alkalinity is not lessened, 

 and the sugar-content remains the same. 



Few aspects of the chemical composition of the blood are more im- 

 portant than that of its electrolytic conductivity by means of ions, for 

 on the relative number of its molecules and its ions depends probably 

 much of the osmotic force everywhere exerted by the blood and lymph. 

 On every hand we have seen the importance of osmosis and diffusion 

 in bodily functions, and few of the physiological processes are inde- 

 pendent of these physical processes. It has been found that so far as 

 determining osmotic pressure is concerned, an ion acts exactly like a 

 complete molecule. Hence the relative degree of dissociation into ions 

 which the body-liquids exhibit under various conditions determines very 

 largely most of the -functions of the organism. According to the recently 

 suggested electrical theory of organic functioning, the more dilute an 

 electrolyte, for example the blood, is, the more ions does it contain and 

 the better it conducts the supposed complicated electric currents of the 

 body's action. Because of their membranous nature, the blood-cor- 

 puscles impede the passage of the ions which bear the electricity, while 

 the plasma is an excellent electrical conductor. The fewer the corpuscles 

 in blood proportional to the plasma, then, the better the blood's conduc- 

 tivity. Again, the more ions or molecules a solution contains the greater 

 is its osmotic pressure through the animal-membranes (the capillary 

 walls, cell-walls, Bowman's capsule, etc.) of the organism. The cor- 

 puscles of the blood are in this category, so that interchanges are con- 

 tinually taking place between them and the plasma as the degree of dis- 

 sociation of their ions and the concentration of the electrolytes determine. 

 It is not only the "inorganic" salts of the blood that furnish the ions, but 

 the colloidal proteids and "extractives" as well. Because, however, 

 of the large molecules of the proteids and of some of the extractives, the 

 osmotic pressure exerted by these substances is small compared with 

 that of the "inorganic" salts. On the other hand, the saline solutions 

 osmose very readily and quickly and by this action largely control the 

 passage of the blood's nutrients and of the tissue- waste in and out of the 

 circulation and the tissues. It is on these principles (here only rudely 

 outlined) that the composition of the blood in these ionic respects is of 

 the largest importance. This composition has control not only over 

 metabolism by chemical means, but also in other ways which chemo- 

 physics will doubtless soon make more clear. 



WHOLE BLOOD'S COMPOSITION (Schmidt). 



Water 788.71 



Proteids and extractives 191.78 



Fibrin (from fibrinogen) 3 . 93 



Hematin (and iron) 7.70 



Salts , 7.88 



1000.00 



