234 COLLOIDS IN BIOLOGY AND MEDICINE 



the skin (PADTBERG). In salt starvation the skin acts conversely, 

 suffering 60-90 per cent of the chlorid loss. [The ancient name for 

 eczema was "salt rheum"; see also " Karell Treatment," J. G. M. 

 BULLOWA, Amer. Medicine, June, 1918. Tr.] 



For animals, an intravenous injection of potassium salts acts as 

 a . poison (especially for cardiac muscle and peripheral vessels) ; 

 thus, according to HELD, even solutions with 0.08 per cent KC1 

 affect frogs and rabbits. By way of the intestinal tract, potassium 

 salts are relatively harmless. HELD * showed that when thus in- 

 troduced, the K was stored in the tissues and only slowly given up 

 to the blood. Here we observe the same phenomena as with water, 

 of which an excess is also taken up by the tissues. 



For the maintenance of the osmotic pressure, a definite concen- 

 tration of any crystalloid suffices. Observations of the most differ- 

 ent kind teach us that exactly that electrolyte which is normally found, 

 is necessary for function and development. If in a suspension of 

 blood corpuscles the NaCl is replaced by sugar, hemolysis becomes 

 more difficult, even though the osmotic pressure is identical. Ex- 

 periments on excised hearts prove that the action of the heart is re- 

 tained much longer if it is perfused with a fluid containing a proper 

 quantity of K, Ca, Mg, P0 4 , than if only physiological salt solution 

 is used. Na, K, Mg and Ca salts are individually poisonous for 

 plants, but mixed in the proper proportions they are absolutely 

 necessary. In Chapter XXII, there are further examples. 



Evidently the condition of swelling required for normal function 

 is afforded by a proper balance in the mixture of electrolytes. 



A. B. MAC ALLUM 1 investigated microchemically the distribution of K, 

 Fe, Ca, Cl and PO 4 in many animal and plant cells, and from his investi- 

 gation made deductions concerning their functional significance, to which 

 we shall again return (see p. 292) . TH. WEEVERS has elaborated them 

 with far reaching studies of the distribution of potassium in plant cells. 



[W. BURRIDGE, Quarterly Journal of Medicine, 10, No. 39, p. 172, 

 aptly remarks that analyses of the blood ash give little information con- 

 cerning the balance of its salts by reason of the fact that the propor- 

 tions of them which are in " sorption " or in solution may vary. Tr.] 



1 A. B. MACALLUM proceeds in part from the fact that inorganic salts increase 

 the surface tension of an aqueous solution, and as a result the surface contains a 

 more dilute solution. Conversely the author concludes that the surface tension 

 is diminished at the points of the cells which are approached by the salts in 

 question. We cannot agree with this conclusion at present, because not only 

 mechanical but chemical influences may determine the adsorption of salts. For 

 instance, L. MICHAELIS and P. RONA (as the author has mentioned) demonstrated 

 that certain kinds of sugar have no influence on the surface tension and yet may 

 be adsorbed. 



