382 On ALLANITE, a new 
was effected in each by means of heat, though not without con- 
fiderable difficulty. The folutions had an auftere, 2Nd flightly 
{wectith tafte. When examined by re-agents, they exhibited 
the following properties : 
(1.) Pruffiate of potafh. A white precipitate. 
(2.) Oxalate of ammonia. A white precipitate. 
(3-) Tartrate of potafh. A white precipitate. 
(4.) Hydrofulphuret of potafh. A white precipitate. 
(5-) Phofphate of {.da.. A white precipitate. 
(6.) Arfeniate of potafh. A white precipitate. 
(7-) Potafh and its carbonate. A white precipitate. 
(8.) Carbonate of ammonia. A white precipitate. 
(9.) Ammonia. A white gelatinous precipitate. 
(10.) A plate of zinc. No change. 
THESE properties indicated Oxide of Cerium. I was there- 
fore difpofed to confider the fubftance which I had obtained as 
oxide of cerium. But on perufing the accounts of that fub- 
ftance, given by the celebrated chemifts to whofe labours we 
are indebted for our knowledge of it, there were feveral cir- 
cumftances of ambiguity which occurred. My powder was 
diffolved in acids with much greater difficulty than appeared 
to be the cafe with oxide of certum. The colour of my oxide, 
when obtained from oxalate, by expofing it to a red heat, was 
much lighter, and more inclined to yellow, than the oxide of 
cerium, 
In this uncertainty, Dr WotLtaston, to whom I communi- 
cated my difficulties, offered to fend me down a fpecimen of 
the mineral called cerife, that I might extract from it real oxide 
of cerium, and compare my oxide with it. This offer I thank- 
fully 
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