EXPERIMENTS ON CER1TE. \QJ 



of galls, a brown, floeculent fediment, unaffecled by muriatic 

 acid. Carbonate of potafli, a very copious while gelatinous, 

 precipitate. Cauftic potafli, the fame : and an excefs of this 

 reagent produced no change. Oxalate of ammonia, a very 

 copious, white, floeculent precipitate, infoluble in an excels 

 of oxalic acid. Sulphuric acid, a yellow cryftalline precipitate 

 foluble in water. Muriate of tin whitened the folution without 

 forming any precipitate. 



Exp. 3. After this the folution was evaporated, when it Attempts to free 

 inftantly became turbid, and formed an abundant flelh-coloured l rom iron * 

 depofit. This was treated with acidulous oxalate of potafn to 

 diflblve the iron without fuccefs : the addition of nitric acid 

 was as unfuccefsful : but muriatic acid added to the preceding 

 diflblved the precipitate with effervefcence and the emiffion of 

 oxigenated muriatic acid gas. A white cryftalline fubftance 

 however, remained, confiding of oxide of cerium with oxalic 

 acid. The greater part of the excefs of acid in the folution 

 being falurated with ammonia, oxalate of ammonia was added 

 till no more precipitate was formed. This precipitate had all 

 the properties of oxalate of cerium. Ammonia threw down 

 from the filtered liquor oxide of iron. 



Exp. 4. The matter precipitated from the folution of cerium Muriate pred- 

 by ammonia in Exp. 2, diflblved with effervefcence in muriatic faJ^f ammonia." 

 acid. Oxalate of ammonia threw down from this folution 

 oxide of cerium, and the filtered liquor contained oxide of 

 iron tolerably pure. 



. Exp. 5, The liquor freed from the greater part of the iron Nitrate precipi- 

 by ammonia and heat, which had notwithstanding a flight pp* ^j^J^T 

 feate tinge, was precipitated by oxalate of ammonia. The 

 precipitate at the moment of its formation had the appearance 

 of muriate of filver, but Won became granulous and fubfided * 



in this form. The liquor patted through the filter colourlefs, 

 and the rofy tinge remained in the oxalate.. 



Exp. 6. As the liquor from which the oxalate of cerium was Oxalate of lime 

 precipitated contained an excefs of acid, it might be prefumed feparate ' 

 to hold in folution mod of the oxalate of lime formed at the 

 fame time, if the cerite contained any. Accordingly it was 

 mixed with the water that had wafhed the precipitate and con- 

 centrated by evaporation, when on the addition of ammonia a 

 imal! quantity of oxalate of lime was thrown down. 



Exp. 7. As notwithftanding fome oxalate of lime might have R eft of the lime, 

 been precipitated with the oxalate of cerium, a portion of the '^P 313 ^' 1, 



red 



