76 DYNAMICS OF LIVING MATTER 



Water 1000 g. 



NaCl ......... 6 g. 



KC1 0.075 g- 



CaCl 2 ......... o.i g. 



NaHCO 3 o.i g. 



Rusch has applied this solution with success for the isolated heart 

 of warm-blooded animals, with the difference only that he added 8 g. 

 instead of 6 g. of NaCl to 1000 g. of water. 



Locke * recommends the following solution for the isolated heart 

 of the rabbit: 



Water 1000 g. 



NaCl 9.10 g. 



KC1 ......... 0.2 g. 



CaCL, ......... 0.2 g. 



NaHCO 3 o.i g. 



The solution is said to be more effective if a little dextrose is added, 



i g- 



Otherwise Locke's solution differs from Ringer's by a somewhat 



higher amount of KC1 and CaCl 2 . His figures for these latter salts 

 are approximately those which Abderhalden found for the concen- 

 tration of these salts in the serum of rabbits; namely, 0.024 per cent 

 CaCl 2 and 0.042 per cent KCl.f 



If we express the percentage solutions of Ringer, Locke, or Abder- 

 halden, in the values of grammolecular solutions, we find that it is 

 approximately 100 molecules NaCl to 2 molecules of CaCl 2 . This 

 is practically the proportion in which these salts exist in the sea water, 

 and in which marine animals live longest. This proportion may vary 

 a little for marine animals, and the same is true for the solutions in 

 which the tissues of animals live best, as a comparison of the figures 

 of Ringer and Locke shows. 



An observation mentioned already in a former lecture shows con- 

 clusively that the mixture of 100 NaCl, 2 KC1, and 2 CaCl 2 cannot be 

 considered as a nutritive solution for animals, but must play a different 

 role. Fundulus lives just as well in distilled water as in sea water. 

 This fact proves that these animals do not depend for their nutrition 



* Locke, Centralblatt fur Physiologie, Vol. 14, p. 670, 1901. 



t The fact that Locke also mentions sugar as one of the necessary constituents of his 

 solution indicates that he considers the other constituents also as nutritive material. This 

 would, however, be wrong. From my own experiments I do not think that the addition of 

 sugar is of any value. 



