tailed the Gadolinite. 369 



muriatic; and, if their action be afiifted by a gentle heat, 

 they form a thick jelly of a grayifh or yellowifh colour. 

 If this kind of jelly be then evaporated to drynefs, and the 

 refiduum of the evaporation be wafhed in water, you will 

 obtain filex under the form of a white powder, which, when 

 well wafhed and brought to a red heat, gives by its weight 

 the proportion in which it exifts with the other principles. 



The folutions of gadolinite in acids do not all exhibit the 

 fame phenomena by evaporation. The fulphuric and mu- 

 riatic acids retain the iron and the new earth in combina- 

 tion, and nothing but the filex is feparated ; while, on the 

 contrary, the nitric acid abandons at the fame time the files 

 and the oxyd of iron, which may be eafily conceived from 

 the properties of the nitrat of iron. 



I took advantage of this property in preference to any 

 ether, in order to apply it to the analyfis in queftion. 



I diffolved jop parts of gadolinite in nitric acid fufficfently 

 diluted with water, and fubjected it to evaporation, expofing 

 it to a little heat towards the end, to effect a complete de- 

 eompofition of the nitrat of iron. By re-diflblving it in 

 water, I obtained, combined with the nitric acid and dif- 

 folved, the peculiar earth feparated from the iron and the 

 filex. While my folution (till retained fome traces of iron, 

 which I eafily perceived either by the reddifh colour or by 

 the gallic acid, I again evaporated the liquor to drynefs, or 

 I added a drop of ammonia, and the iron was then precipi- 

 tated under the form of yellowifh flakes, which I feparated 

 fey the filter. 



To feparate the iron from the filex, I boiled the mixture 

 m muriatic acid a little concentrated ; I then diluted the 

 folution with water, and made it pafs through the filter, in 

 erder that I might collect the filex, and wafh it till it was no 

 longer precipitated by ammonia. 



In regard to the new earth diffolved in nitric acid, it will 

 be fufficient if it be pure to precipitate it by ammonia, and 

 to wafh it to obtain it feparate; but having learned, by prcr 

 liminary trials, that in this ftate it is mixed with fmall quan- 

 tities of lime and magnefia, I was obliged to employ fome 

 further means for accomplifhing that end, 



I never- 



