302 



COLLOIDS IN BIOLOGY AND MEDICINE 



There are no exhaustive investigations on the influence of salts 

 upon the internal friction of proteins in normal serum. Yet it 

 seems possible to conclude from the figures of Wo. PAULI and 

 H. HANDOVSKY that the friction in serum in the presence of salts is 

 approximately the same as in a salt-free albumin solution; however, 

 it must not be forgotten that the solutions investigated possessed a 

 much smaller amount of albumin than does serum. 



We see that when the solution of salt is very dilute, the internal 

 friction may even sink, but that between 0.1 and 0.5 n which is in 

 the neighborhood of the physiological concentration (physiological 

 salt solution 0.85 per cent NaCl = 0.14 normal), the original inter- 

 nal friction of the salt-free albumin solution is again reached and 

 exceeded. 



A matter formerly very much discussed was whether some electro- 

 lytes and nonelectrolytes, especially sugar, chlorin, phosphate, 

 sodium and calcium, exist in the blood free or fixed. In the light of 

 the facts this does not seem to be a correct statement of the problem. 

 It is more important to determine what percentage of the ions 

 involved are diffusible. B. P. RONA and GYORGY by ultrafilt ration of 

 C0 2 -sera have demonstrated that 10 to 15 per cent of the Na in some 

 sera was not diffusible. P. RONA and D. TAKAHASHI * determined that 

 25 to 35 per cent of the calcium in the serum is not diffusible and 

 probably exists as a calcium protein compound. The Cl ion, on the 

 contrary, was found to be completely diffusible. 



We know from pages 147 and 161 that the solubility of salts in 

 solutions of hydrophile colloids is very different from what it is 

 in pure water. As a matter of fact, the solubility of easily soluble 

 electrolytes is somewhat diminished and that of the difficultly 

 soluble ones is markedly increased. If we make a solution of salts 

 of the same strength and proportion per liter as occurs in natural 

 serum (see H. M. ABLER *) 



KC1 0. 40 



CaCl 2 + 6 aq 0.62 



MgCl 2 + 6 aq 0.37 



NaCl 5.90 



NaH 2 PO 4 + 1 aq 0.236 



NaHCOa 3.51 



