T. S. Hunt on some American Minerals. 345 
reddish-brown precipitate; it was regarded as titanic acid. The 
amount precipitated by prolonged ebullition was ‘096 grammes 
=58'5 percent. ‘The filtrate gave with ammonia a small amount 
of reddish gelatinous precipitate, which contained a trace of oxyd 
of iron; it was examined without success for alumina, and gave 
with sulphate of potash no satisfactory evidence of the presence 
of oxyd of cerium; it was perhaps only titanic acid; the ammo- 
niacal filtrate gave about 10 per cent. of lime. An accident hav- 
Ing occurred at this stage of the process, I had no means of deter- 
mining whether there were present any other ingredients than 
hitanic acid and lime, but I hope for a farther supply of the min- 
eral which may enable me to complete its analysis. Meanwhile 
by its specific gravity, which is greater than that of perovskite or 
polymignite, it is distinguished from any titanate hitherto de- 
scribed, and is entitled’ to the rank of a distinct species. 
_ Prof. Shepard in his qualitative examination of the rutherford- 
ite, having separated a portion of titanic acid by boiling the sul- 
Phuric solution, added ammonia to the liquid and obtained a pre- 
Cipitate, which when redissolved in hydrochloric acid and mixed 
with a solution of sulphate of potash gave a very copious granu- 
lar precipitate, in which, from some characters, he suspected the 
Presence of oxyd of cerium, It is not improbable that this reac- 
tion arose from the presence of a peculiar form of titanic acid, 
which has never to my knowledge been described. | 
The sulphuric solution of ignited titanic acid is not affected by 
sulphate of potash, and the titanic acid precipitated by ammonia 
from this solution, and redissolved in hydrochloric acid, gives no 
_ Precipitate either with sulphuric acid or a solution of sulphate of 
potash. however the sulphuric solution is heated to boiling, 
80 as to precipitate a small portion of the titanic acid,’ that which 
remains dissolved is found to have acquired peculiar properties. 
If it is thrown down by ammonia, carefully washed and dis- 
solved in dilute hydrochloric acid, the solution is scarcely dis- 
turbed by ebullition, but the addition of a few drops of dilute 
sulphuric acid, a erystal of sulphate of potash, or any soluble sul- 
phate, in the cold, produces an immediate copious, white, floceu- 
ent precipitate, which includes almost all of the titanic acid pres- 
t may be washed with water, in which it is insoluble, and 
seems to contain but a trace of sulphuric acid; it is soluble 
to a considerable extent in heated dilute hydrochloric acid, from 
It is also somewhat solu- 
he hydrochloric solution of the ordinary form of titanic acid, 
assumes the same characters when heated to ebullition. 
