378 COLLOIDS IN BIOLOGY AND MEDICINE 



Salts. 



The neutral salts of alkalis may cause injuries 1 to organs or 

 organ groups by reversible changes in the condition of the organ 

 colloids; strictly speaking, they are not poisons. We are unable 

 to produce a poisoning, for instance by the oral ingestion of moderate 

 doses of potassium salts, though this may be accomplished with 

 intravenous injections; under such circumstances, disturbances of the 

 heart muscle and the peripheral vessels are observed. It would be 

 worth determining whether these phenomena are not to a great 

 extent caused by changes in the viscosity of the blood. Hitherto, 

 potassium salts have not been purposely employed therapeutically 

 with this in view. H. BECHHOLD and J. ZiEGLER* 3 attribute the 

 favorable action of a vegetarian diet in gout to the generous supply 

 of potassium salts which hinders the precipitation of urates. 



The biological action of neutral salts has been studied chiefly 

 by biologists and physiologists. We owe to them valuable contri- 

 butions concerning the inhibition of irritability (see p. 274 et seq.), 

 the death of lower salt and fresh water organisms in changed media, 

 and the inhibition of the development of the eggs of marine 

 creatures. 



It follows from all these investigations that for the normal function- 

 ing of the organisms, no matter whether animal or plant, high or low, 

 a definite combination of electrolytes is necessary; upon this the 

 normal state of swelling for the organ colloids depends. The cations 

 are especially important. The monovalent cations (Na, K) are held 

 in check by small quantities of divalent ones (Ca, Mg) . [See CLOWES, 

 p. 38. Tr.] Several examples may serve to explain this. For ani- 

 mal organisms a given content of Na ions is necessary, which may 

 at best be replaced by Li ions. K ipns are especially poisonous because 

 they change the state of turgescence of the organ colloids. Pure 

 sodium chlorid solution of physiological osmotic pressure behaves as 

 a poison; this was shown by JACQUES LOEB on the fertilized eggs 

 of fundulus heteroclitus, a small sea anemone. He also showed 

 that this poisonous action was arrested by the addition of a small 

 amount of any salt containing polyvalent cations. Substances which 

 were themselves very poisonous, such as barium, zinc, lead and ura- 

 nium salts, under these circumstances detoxicate sodium chlorid, but 

 copper and mercury salts and ferric ions showed no detoxicating 

 action. K. G. LILLIE * 1 observed a similar antitoxic action of poly- 

 valent cations in the poisoning of the larval forms of arenicola, a sea 

 annelid. Its ciliary movement is stopped by pure Na and Li salts 



1 These questions are treated in Chapter XVII. 



