MUSCULAR TWITCHINGS 749 



soluble calcium salt, the twitchings will not occur, though 

 the muscle lives longer in such a solution than in a pure 

 sodium-chloride solution. I concluded from this that we 

 owe it to the calcium, ions in the blood that our muscles do 

 not twitch or beat rhythmically like our heart. 1 



To test this idea further, Mr. W. E. Garrey and I under- 

 took, in 1889, a series of experiments, not yet published, on 

 the behavior of muscles in solutions of sodium salts whose 

 anions precipitate calcium. The muscle itself contains cal- 

 cium salts, and we considered it likely that these calcium 

 salts might help in preventing contractions. We therefore 

 thought that by putting the muscle into solutions of sodium 

 salts, which, by entering the muscle, precipitate the calcium 

 contained in it, we might produce still more powerful rhyth- 

 mical contractions than in a pure sodium-chloride solution. 

 This was found to be true. In solutions of sodium-fluoride, 

 -oxalate, -carbonate, -phosphate, etc., of the proper concen- 

 tration (1 gram-molecule in 8 liters of the solution), we 

 obtained similar, but more powerful, rhythmical contractions 

 than in sodium-chloride solutions of the same osmotic pres- 

 sure. Another series of observations confirms the idea that 

 it is due to the calcium salts in our body that our muscles do 

 not show any rhythmical contractions or twitchings. When 

 we inject into the body of an animal any salts that are liable 

 to precipitate calcium, we notice almost immediately twitch- 

 ings of all the muscles. 2 It seems, therefore, rational that in 

 the pathology of muscular twitchings the concentration of 

 the calcium ions in the blood should be taken into considera- 

 tion. It is quite possible that abnormal conditions may arise 

 in the body which lead to an increase of such acids in the 

 circulation as diminish the amount of calcium ions in the 



1 Part II, p. 518. See also S. RINGEB, Journal of Physiology, Vol. VII (1886) , p. 291 

 In this paper Ringer also mentions briefly the fact that Ba differs in its action from 

 Ca and Sr. 



2 FRIEDENTHAL, Engelmanri'a Archiv, 1901, p. 145. 



