354 On the Chemical Constitution of Warwickite. 
A’ ‘250 grammes of the powder were intensely ignited for 
_ some minutes in a platinum crucible; the loss of weight was 
‘004, and the color became of a lighter reddish brown. Sulphu- 
ric acid diluted with its bulk of water was now added, and the 
eral before ignition, gave the same negative result. By a pro- 
longed digestion with the acid, the whole was converted into a 
white mass, which was completely soluble in warm water, 
evincing the absence of silica. : 
. The recent solution prepared in a carefully covered cruci- 
ble, gave with ferrocyanid of potassium a pale greenish-blue pre- 
cipitate, but with the ferrideyanid an immediate precipitate of a 
was 
chloric acid, boiled, and ammonia added ; th 
liquid was disturbed only by the separation of a trace of precipl- | 
tate too small to be estimated ; this was regarded as titanic acid 
which “is not wholly insoluble in carbonate of ammonia. Th 
-ammoniacal solution gave with phosphate of soda a precipitate 
of ammonio-phosphate of magnesia. 
E. The insoluble residue from the last, having been dissolved 
drop or two of dilute sulphuric acid and, boiled, yielded a 
peroxyd of iron. Its nature was verified by redissolving it, add- 
ing tartaric acid and ammonia in excess, and precipitating the 
_ metal as sulphuret. 
-F. The ammoniacal filtrate from C was not affected by hy- 
_ drosuTphuret or oxalate of ammonia, but gave by the addition of 
; Sees sda a copious precipitate of phosphate of, magne- 
sia and ammonia, "A portion of the solution evaporated to 2 
"ness and ignited to expel ammoniacal salts, was precipitated PY 
id ag age = 
