MINERAL from GREENLAND. 377 



found them quite different. Convinced by thefe experiments, 

 that the mineral contained no yttria, but that one of its confti- 

 tuents was a fubftance with which I was ftill unacquainted, I 

 had recourfe to the following mode of analyfis, in order to ob- 

 tain this fubftance in a pure ftate. 



III. Analysis of allanite. 



i. 100 grains of the mineral, previoufly reduced to a fine 

 powder, were digefted in hot nitric acid till nothing more 

 could be difTolved. The undiffolved refidue, which was filica, 

 mixed with fome fcales of mica, weighed, after being heated to 

 rednefs, 35.4 grains. 



2* The nitric acid folution was tranfparent, and of a light- 

 brown colour. When flrongly concentrated by evaporation, 

 to get rid of the excefs of acid, and fet afide in an open capfule, 

 it concreted into a whitifh folid matter, confining chiefly of 

 foft cryflals, nearly colourlefs, having only a flight tinge of 

 yellow. Thefe cryflals being left expofed to the air, became 

 gradually moifl, but did not fpeedily deliquefce. The whole 

 was therefore difTolved in water, and the excefs of acid, which 

 was ftill prefent, carefully neutralifed with ammonia. By this 

 treatment, the folution acquired a much deeper brown colour ; 

 but ftill continued tranfparent. Succinate of ammonia was 

 then dropped in with caution. A copious reddifh-brown pre- 

 cipitate fell, which being warned, dried, and heated to rednefs 

 in a covered crucible, weighed 25.4 grains. It poffefTed all 

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

 the magnet, completely foluble in muriatic acid, and the folu- 

 tion was not precipitated by oxalate of ammonia. 



3. The liquid being ftill of a brown colour, I conceived it 

 not to be completely free from iron. On this account, an ad- 



Vol. VI. P. II. 3 B ditional 



