10 



PROCEEDINGS OP THE AMERICAN ACADEMY 



The general result of my own study of the action of acetic acid upon 

 the neutral tungstate is, that we obtain the 12 : 5, the 22: 9, or the 10:4 

 salt, according to the circumstances of the case, the constitution of the 

 salt formed depending mainly upon the degree of concentration of the 

 acid and upon the duration of its action. These results are in no way 

 inconsistent with those of Lefort, and his analyses seem to leave no 

 reasonable doubt that he obtained various salts to be classed as ditung- 

 states and fcritungstatea. 



Potassic Tuvgstates. — When a hot solution of the 10 : 4 sodium salt 

 is mixed with a hot solution of potassic nitrate, a white precipitate 

 shortly appears in small colorless crystalline scales, which may lie re- 

 crystallized by projecting them in very small quantities at a time into 

 boiling water. This method, which was first given by Scheibler, 

 enables us to redissolve the salt in water without loss from the exces- 

 sively violent succussions which occur on heating the salt with water 

 in the usual manner. The salt requires a rather large quantity of 

 water for solution, and crystallizes almost completely from the cold 

 liquid. Of this salt in the first preparation, — 



Mean of the four determinations of water in the first preparation. 



