OWEN'S DESCRIPTION OF TWO NEW MINERALS AND A NEW EARTH. 181 



Bi-carbonate of potash, white precipitate; apparently slightly soluble in excess. 



Phosphate of soda and ammonia. The vesicular precipitate with this reagent is 

 quite peculiar, and forms one of the marked characteristics of this earth. If the 

 reagent be added without disturbing the fluid, a number of little vesicles are formed, 

 which remain distinct, as if each were enclosed in a delicate translucent membrane. 



Ferro-cyanide of potash, a white precipitate, with a slight tinge of blueish green, 

 which seemed to be independent of any remaining trace of oxide of iron ; perhaps 

 in part due to the color of the reagent itself 



Hydrosulphuret of ammonia, a white precipitate. 



Succinate of ammonia, a white precipitate even in slightly acid solutions. 



Benzoate of ammonia, the same, with a tinge of yellow. 



Crystals of sulphate of potash inserted in the solution gave but a very slight 

 precipitate, and that only after long standing. 



The precipitate of phosphate of soda is only soluble in a considerable portion of 

 muriatic acid, and is not precipitated by boiling. 



When separated, and still slightly contaminated with magnesia, the earth has a 

 pale flesh color, not unlike yttria. When freed from the magnesia it has more the 

 appearance of powdered, dried albumen. 



The earth differs from alumina and glucina in being insoluble in caustic potash. 



From magnesia, in producing colored salts ; in being only slightly soluble in 

 ammoniacal salts ; in the peculiar vesicular character of the precipitate with phosphate 

 of soda; in being precipitated by oxalate of ammonia. 



From yttria it differs in not giving a precipitate with oxalic acid in slightly acid 

 solutions ; in being precipitated by succinate of ammonia, even before the solution is 

 quite neutral, which prevents this reagent being applied to separate iron from it, as 

 is recommended by Berzelius for separating iron from oxide of yttria. 



It differs from zirconium, in being soluble in nitric and muriatic acids, after 

 ignition. 



From cerium, in not turning of a brick red after ignition : and in the color of its 

 salts, which are not amethystine but shades of green and yellow, except the nitrate, 

 which is almost colorless. 



The nitrate crystallizes in prisms which seem to be right rhombic. 



Its salt, like the corresponding ones of magnesia, seem to be deliquescent. 



The mineral from which this earth was extracted differs from talc, in the absence 

 of any foliated structure ; in not exfoliating before the blow-pipe ; in giving off" water 

 in the matrass, which talc does not, being quite anhydrous, while this is a hydrated ' 

 silicate. It contains 20 per cent, less silica than talc. 



Leaving out of account the earth in question, the chemical constitution of this 

 mineral comes nearest to saponite and soap stone. The specimens of saponite or 



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