512 STUDIES IN GENERAL PHYSIOLOGY 



water by muscle. I must, however, call attention to the 

 fact that Wallace and Cushny did not continue their ex- 

 periments long enough" to allow them to draw such a con- 

 clusion. In the course of one hour a muscle increases about 

 2 per cent, in weight in a KC1 solution; in a CaCl 3 solution 

 it decreases about 3-5 per cent. ; in a LiCl or a NaCl solu- 

 tion its weight remains unchanged. The experiments of 

 Wallace and Cushny lasted less than one hour, and to dis- 

 cover such slight variations as those given in my experi- 

 ments is impossible in those of Wallace and Cushny. 



In what way, now, can we imagine that potassium salts 

 bring about a positive, calcium salts a negative, absorption 

 of water in muscle? When we place a muscle into any of 

 the solutions mentioned above, Li, Na, K, and Ca ions soon 

 begin to diffuse into the muscle. Just as in case of soaps 

 this would lead to the formation of Na, K, and Ca soaps, it 

 might lead in muscle to the formation of Na, K, and Ca com- 

 pounds, which behave like the corresponding soaps in at least 

 one particular in their power of dissolving water. 1 



It is of importance, for what has been said, that SrCl 2 , 

 BaCl 3 , CoCl 2 , and MnCl g behave like CaCl 3 . MgCl 3 , 

 however, is much weaker in its action than these. Table II 

 shows the weight lost by muscles when immersed in equi- 

 molecular solutions of these five salts. 



TABLE II 



The loss in weight of muscle (in per cent, of its original weight) in solutions equi- 

 molecular with a 0.7 per cent. NaCl solution. Length of the experiment, eight- 

 een hours. 



MgCl 2 ....... 4.7^ CoCl 2 ......... 



BaCL ....... -12.0 MnCl 2 ........ -39 



SrCl 2 ....... -18.0 



Perhaps the solutions of all the heavy metals will fall 

 into this group; that is to say, they will all bring about a 

 loss of water in muscle. 



1 Or of absorbing water. 



