TUNGSTEN. 65 



it appears, that the oxygen in the protoxide is 

 to that in the peroxide as 2 to 3 ; so that, if the 

 protoxide be a compound of 1 atom tungsten 

 and 1 atom oxygen, the peroxide must be a com- 

 pound of 1 atom tungsten and li atom oxygen. 

 Thus we see that the oxides of tungsten in this 

 respect resemble the oxides of iron, nickel, co- 

 balt, and cerium. 



I shall now state the experiments which I 



of ammo- 

 made, in order to ascertain the atomic weight of nia 



tungstic acid. 



1. I first prepared a considerable quantity of 

 tungstate of ammonia from wolfram, by heating 

 wolfram in powder alternately in muriatic acid 

 and ammonia, till the mineral was decomposed. 

 The ammoniacal solutions, when properly con- 

 centrated, deposited the tungstate of ammonia in 

 small brilliant crystals. 



Of this tungstate I obtained two different va- 

 rieties. The first was crystallized in four-sided 

 rectangular prisms with rhombic bases. When 

 put into the mouth this salt appeared at first 

 tasteless, but in a short time it left a bitter im- 

 pression on the palate, which was succeeded by 

 a certain degree of sweetness mixed with a disa- 

 greeable metallic taste. This salt was so very 

 sparingly soluble in water, that the solution did 

 not answer well for determining the effect of re- 

 agents upon tungstic acid salts. 



But in some of my other processes, I got a 



VOL. II. E 



