godoHnite, which had been reicived directly from Mr* 

 Ekeberg. From this [ extracted about 10 grain* of yttria; 

 and upon comparing its properties with those of the sub- 

 stance in quetitiou, I found them quite different. Con- 

 ▼inced by these experiments, that the mineral contained no 

 yttria, but that one of its constituents was a substance with 

 which I was still unacquainted, I had recourse to the fol- 

 lowing mode of analysis, in order to obtain this substance in 

 a pure state. 

 Analysis. ^^^^' ^^^' '• ^^^ grains of the mineral, previously reduced 



ton tine powder, were digested in hot nitric acid, till nothing 

 SUex. more could be dissolved. The undissolved residue, which 



was silica, mixed with some scales of mica, weighed, after 

 being heated to redness, 35'4 grains. 

 Oxidtoftron. 2. The nitric acid solution was transparent, and of a light 

 brown colour. AVhen strongly concentrated by evaporation, 

 to get rid of the excess of acid, and set aside in an open cap- 

 sule, it concreted into a whitish solid matter, consisting 

 chiefly of soft crystals, nearly colourless, having only a slight 

 tinge of yellow. These crystals, being left exposed to the 

 air, became gradually moist, but did not speedily deli* 

 quesce. The whole was therefore dissolved in water, and 

 the excess of acid, which was still present, carefully neu- 

 tralised with ammonia. By this treatment the solution ac- 

 quired a much deeper brown colour; but it still continued 

 transparent. Succinate of ammonia was then dropped in 

 "with caution. A copious reddish-brown precipitate fell, 

 which being washed, dried, and heated to redness in a 

 covered crucible, weighed 25*4 grains. It possessed all the 

 characters of black oxide of iron. For it was attracted by 

 the magnet, completely soluble in muriatic acid, and the 

 solution was not precipitated by oxalate of ammonia. 

 Another preci- 31. The liquid being still of a brown colour, I conceived 

 pi ate thrown ,j^ ^^^ ^^ ^^ completely free from iron. On this account, an 

 additional quantity of succinate of ammonia was added. 

 A new precipitate fell ; but instead of the dark reddish- 

 brown colour, wliich characterises succinate of iron, it hod n 

 beautiful flesh-red colour, which it retained after beinp 

 dried in the open air. W hen heated to redness in u covered 



crucible. 



