188 The Mechanistic Conception of Life 



IX 

 The objection might be raised that the beneficial action of 

 the three salts could only be proved on marine animals or on 

 tissues of higher animals, which are said to be '^ adapted" to a 

 mixture of NaCl, KCl, and CaCl., in definite proportions. 

 Experiments on fresh-water organisms, for which ^'adaptation" 

 to a mixture of NaCl, KCl, and CaCl, in these definite propor- 

 tions cannot be claimed, show that this objection is not valid. 

 Ostwald worked with fresh-water crustaceans which he put into 

 mixtures of various salts. It was found that these animals 

 live longer in a mixture of NaCl + KCl +CaClo than in a solu- 

 tion of NaCl, or NaCl+KCl, or NaCl+CaCl, of the same 

 osmotic pressure. 



Osterhout was able to show that the spores of a certain 

 variety of Vaucheria die in a pure 3/32 m solution of NaCl in 

 10 to 20 minutes, while they live in 100 c.c. 3/32 m NaCl + 1 c.c. 

 3/32 CaClg 2 to 4 weeks, and in 100 c.c. 3/32 m NaCl + 1 c.c. 

 3/32 m CaCl,+2.2 c.c. 3/32 m KCl 6 to 8 weeks. The reac- 

 tion of the solution was strictly neutral and the NaCl the purest 

 obtainable. The results remained the same after the NaCl 

 had been recrystallized six times. Experiments with Spirogyra 

 gave a similar result. The solutions were all 3/32 m. In 

 NaCl the Spirogyra died in 18 hours; in NaCl+KCl in two 

 days; in NaCl+KCl+CaCl, they lived 65 days. Osterhout 

 caused wheat grains to develop in such solutions and measured 

 the total length of the roots formed. 



Total Length of 

 Nature of the Solution Roots after 40 Days 



H2O 740 mm. 



100 c.c. 3/25 NaCl 59 mm. 



100 c.c. 3/25 NaCl+2.0 3/25 CaCL 254 mm. 



100 c.c. 3/25 NaCl+2.0 3/25 CaCl2+2.2 3/25 m KCl 324 mm. 



These cases, to which many other similar observations might 

 be added, prove that the life-preserving effect of the combina- 

 tion of NaCl + KCl +CaCL in definite proportions is not due 



