312 SALTS 



centrated and set aside. It concreted into a 

 white solid matter, which was dried by pressure 

 between folds of blotting paper. Thus prepared, 

 it was a fine white crystalline powder exceeding- 

 ly soluble in water, and reddening vegetable 

 blues. Its taste was astringent and sweet, with 

 an impression of acidity. This salt was analyzed 

 in the following manner : 



22-5 grains of it were exposed to a red heat, 

 and kept at that temperature till nothing re- 

 mained but the alumina, which weighed exactly 

 4\5 grains. 



Q&5 grains of the salt were dissolved in water, 

 and the solution digested in a flask with carbo- 

 nate of barytes the alumina was thrown down, 

 and a solution of nitrate of barytes formed. 

 This solution being evaporated to dryness, left 

 16'245 grains of nitrate of barytes. Now, 

 16*245 grains of nitrate of barytes contain 6'645 

 grains of nitric acid. This approaches so near 

 6-75, that it is evident the salt is a dinitrate, and 

 composed of 



1 atom nitric acid C-?5 



2 atoms alumina 4-5 

 10 atoms water 11-25 



22-5 



I made different attempts to form a nitrate of 

 alumina, but they were all unsuccessful. 

 Trisnitratc, 4. Trisnitratc of alumina. I formed this salt 

 by keeping the dinitrate of alumina on the sand 



