XXXVII 
ON THE PRODUCTION AND SUPPRESSION OF MUSCU- 
LAR TWITCHINGS AND HYPERSENSITIVENESS OF 
THE SKIN BY ELECTROLYTES’ 
Iv 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 (7. 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. 
2Part II, pp. 544, 559, and 692; Pyliigers Archiv, Vol. LXXXVIII (1901), p. 68. 
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