XXXVII 



ON THE PRODUCTION AND SUPPRESSION OF MUSCU- 

 LAR TWITCHINGS AND HYPERSENSITIVENESS OF 

 THE SKIN BY ELECTROLYTES 1 



IT has been shown in former publications that a slight 

 variation in the proportion and character of the electrolytes 

 in a tissue is capable of imparting to that tissue properties 

 which it does not possess ordinarily, and it has been sug- 

 gested that this fact might help us in recognizing the nature 

 of a number of nervous and muscular diseases, and also 

 possibly furnish a means of curing or mitigating them. 

 This paper contains some further contributions to the same 

 subject. It deals with the determination of electrolytes which 

 are liable to produce and inhibit hyperactivity of muscles and 

 hypersensitiveness of the nerves of the skin; and tries to 

 answer the question whether or not the stimulating and 

 inhibiting effects of ions are a function of their valency and 

 electrical charge. 



I. THE PRODUCTION AND SUPPRESSION OF MUSCULAR TWITCH- 

 INGS BY ELECTROLYTES 



1. Our muscles do not normally contract or twitch rhyth- 

 mically, but they do so in certain diseases. The main 

 electrolyte in our blood is sodium chloride. When we put a 

 muscle into a pure sodium-chloride solution of the right 

 osmotic pressure (/. e., isotonic with the muscle), the muscle 

 soon begins to twitch rhythmically, and these twitchings may 

 last for several days, or about as long as the muscle lives. 

 But when we add a very small, though definite, amount of a 



1 University of Chicago Decennial Publications (1902), Vol. X, p. 3. 

 2 Part II, pp. 544, 559, and 692 ; Pflugers Archiv, Vol. LXXXVIII (1901) , p. 68. 



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