380 On ALL AN IT ' E, a new 



temperature, whether thefe acids were concentrated 

 or diluted. 



(16.) A plate of tin put into the nitric folution, occafioned no 

 change. 



(17.) A portion being inclofed in a charcoal crucible, and ex- 

 poied for an hour to the heat of a forge, was not re- 

 duced to a metallic button, nor could any trace of it 

 be detected when the crucible was examined. 



These properties were all that the fmall quantity of the 

 matter in my pofTeffion enabled me to afcertain. They une- 

 quivocally point out a metallic oxide. Upon comparing them 

 with the properties of all the metallic oxides known, none 

 will be found with which this matter exactly agrees. Cerium 

 is trie metal, the oxides of which approach the neareft. The 

 colour is nearly the fame, and both are precipitated white by 

 pruffiate of potafh, fuccinate of ammonia, and benzoate of 

 potafh. But, in other refpects, the two fubftances differ entire- 

 ly. Oxide of cerium is precipitated white by oxalate of am- 

 monia and tartrate of potafh 3 our oxide is not precipitated at 

 all : Oxide of cerium is precipitated white by hydro-fulphuret 

 of ammonia; while our oxide is precipitated black : Oxide of ce- 

 rium is not precipitated by zinc, while our oxide is thrown 

 down black. There are other differences between the two, 

 but thofe which I have jufh mentioned are the mofl ftriking. 



These properties induced me to confider the fubftance 

 which I had obtained from the Greenland mineral as the oxide 

 of a metal hitherto unknown j and I propofed to diftinguifh. it 

 by the name of Junonium. 



In the experiments above detailed, I had expended almoft all 

 the oxide of Junonium which I had in my pofleflion, taking it for 

 granted that I could eafily procure more of it from the Green- 

 land 



