614 LAWRENCE W. COLE 



SUMMARY 



The reaction-times of frogs to 3 m., 2 m., 1 m., and m/2 solu- 

 tions of the chlorides of ammonium, potassium, sodium, and 

 lithium give good grounds for distributing these salts into two 

 groups — -ammonium and potassium; sodium and lithium, an ar- 

 rangement also indicated by their degrees of dissociation. 



The quickest reactions occur generally with the chloride of 

 greatest dissociation. In two chlorides whose degree of dissocia- 

 tion is not widely different, the separation by reaction-times is 

 imperfect though a long series of experiments designed to test 

 this point might yield discriminating results. 



It is probable that the reaction-times to these salts include two 

 factors, diffusion- time and summation-time. The latter seems 

 to be much the shorter. 



The comparisons with the tastes of chlorides of these metals 

 and the results of applying cocaine, suggest that nerves of a 

 general chemical sense rather than pain nerves are affected by the 

 chlorides. 



In conclusion, my thanks are due to Professor G. H. Parker for 

 the plan of the experiments and assistance in the work. 



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Kahlenberg, L. 1898 The action of solutions on the sense of taste. Bull. 

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Kohlratjsch, F., und Holborn, L. 1898 Das Leitvermogen der Elektrolyte 

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Loeb, J. 1902 1st die erregende und hemmende Wirkung der Ionen cine Function 

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