5§ tiltPEBlXENTS 0» AtlANtTI. 



• tastefj^/felt gritty between the teeth, and was easily redace<l 

 to powder. It effervesced in sulphuric, nitric, inuriutic, and 

 acetic acids, and a solution oF it was effected in each by 

 ^ • means of heat, though not without considerable difficulty. 



The solotions had an i:uster^, and slightly sweetish taste* 

 When examined by reagents, they exhibited the following 

 properties : 



examined by (l.) Prussiate of potash. A white precipitate. 



rtrfgtuts, j2.) Oxalate t>f ammonia, A white precipitate. 



(3.) Tartrate of potash, A white precipitate. 



(4.) Hydrosulphuiet of potash. A white precipitate. 



(5.) Phosphate of soda. A white precipita.e. 



(6.) Arseniate of potash. A white precipitate. 



(7.) Potash and its carbon-ate. A white precipitate, 



(8.) Carbonate of ammonia. A white precipitate. 



(9.) Ammonia. A white gelatinous precipitate. 



(10.) A plate of zinc. No change. 



appealed to These properties indicated oxide.of cerium. I was there- 



differ m some I'Qj.g (^^gposed to consider the substance which I had obtained 

 respects from ^ 



that of ce- as oxid^ of cerium. But on perusing the accounts of that 

 rium; substance, given by the celebrated chemists to whose la- 



bours we are indebted for pur knowledge of it, there were 

 several circumstances of ambiguity which occurred. My 

 powder was dissolved in acids with much greater difficulty 

 than appeared to be the case with oxide of cerium. The 

 colour of my oxide, when obtained from oxalate, by ex- 

 posing it to a red heat, was much lighter, and more inclined 

 to. yellow, than the oxide of cerium. 



In this uncertainty. Dr. WoUaston, to whom I communi- 



caied my difficulties, offered to send me down a specimen 



' of the mineral called cerite, that I might extract from it 



real oxide of cerium, and compare my oxide with it. This 



butlhii owing offer I thankfully accepted *; and upon comparing the pro- 



10 the method pe|.tiesof my oxjde with those of oxide of cerium, extracted 



was procured, from cerite, I was fully satisfied that they were identical. The 



more 



♦ The specimen of cerite, which I analysed, was so much mixed with 

 actonolite, that the statement of the results which I obuined canno^ 



be 



