ACCOUNT OP A MINERAL SUBSTANCE, 133 



The liquor from which this precipitate had been feparated ^^^ 

 by nitric acid, was then faturated with ammonia, and, being more - non% 

 toiled, afforded about two grains of oxide of iron. 



I obtained, therefore, from ?00 grains of the ore, 



Grains. Grains. 



Oxide of iron r ? - ^ 2 1 = 197. 



And of the white precipitated fubftance 155 3 

 But, as I could not repeat the analyfis without deftroving 

 tke remaining part of the only fpecimen at prefent known of 

 this ore, I do not wifh the above ftated proportions to be re T 

 garded as rigidly exad; it will be fufficient, therefore, to fay 

 at prefent, that the ore is comppfed of about three parts of the 

 white matter, and rather lefs than one of iron. 



§ II. PROPERTIES OF THE WHITE PRECIPITATE. 



A. 



It is of a pure white, and is not extremely heavy. The white' pre- 



It has fcarcely any perceptible flavour, nor does it appear tq *'P ,tat ? 

 be foluble in boiling water; when, however, fome of the 

 powder is placed upon litmus paper moiftened with diftille4 

 water, the paper in a few minutes evidently becomes red. 



B. 



1 . When examined by the blow-pipe, it is not fufible per is infufible, 

 Je in a fpoon of platina, nor upon charcoal, but only becomes 



of a lefs brilliant white. 



2. Borax does not appear to a£t upon it ; for the white par- not affe&ed by 

 tides are only difperfed throughout the globule, 



3. It produces an effervefcence when fufed with carbonate Soluble by fufion 

 of foda, and forms a colourlefs fait jj but, if too much of it be witil f° da > 

 added, then the mafs, when cold, appears like a white opaque 



enamel. 



4. When carbonate of potafli is employed, the. effects are and with potato, 

 fimilar in every refpect to thofe of foda ; and it may here be 

 remarked, that the faline combinations thus formed with foda, 



or potafli, are foluble in water ; and that thefe folutions have as in the firft 

 the fame properties as that which was formed when the ore decom pofition. 

 was decompofed by an alkali. The portion of the white pre- 

 cipitate which may be in excefs, fubfides unaltered, when the 

 globules are dhTolved in water. 



3 5. Phof- 



