On Cerium, 157 



the cerite in nitric acid, which had been precipitated by 

 caustic ammonia, gave by carbonate of ammonia carbonate 

 of lime. 



It results from these trials that cerite contains nearly 23 

 parts of silex, 5*5 of carbonate of lime, 22 oxide of iron, 

 and a quantity of that matter in a metallic state ; the weight 

 of which after calcination exceeded, a little, 50 per cent. But 

 this substance being then, as well as the iron, united with 

 more oxygen than they contained in the cerite, instead of 

 loss we had an increase of gravity, which in all probability 

 arose from the oxygen. The loss which the cerite had ex- 

 perienced by calcination is not here included. We thus 

 found traces of manganese, but in a quantity so inconsi- 

 derable that the potash fused with cerite and dissolved in 

 water exhibited no colour. 



Not having much experience in regard to complete ana- 

 lysis, as far as quantity is concerned, we give these results 

 only with reserve, and in the hope that more expert che- 

 mists will employ themselves on this object. 



III. Examination of the metallic Oxide found in Cerite. 



With 37 grains of this oxide and linseed oil we made a 

 paste, which was reduced to charcoal in a covered crucible. 

 It lost half a grain of its weight. This mass was inclosed 

 in a crucible of charcoal without flux : and M. Hjelm ex- 

 posed it for half an hour to such a degree of heat as would 

 be necessary for the reduction of manganese. The oxide 

 was not fused, but reduced to a very fine powder : it exhi- 

 bited to the light brilliant particles, and stained white paper 

 black. It dissolved in nuiriatic acid, disengaging at the 

 commencement sulphurated hydrogen gas, and then pure 

 hydrogen gas. This colourless solution had a saccharine 

 taste. It therefore appeared to us that the metal was in part 

 reduced. One may tind the origin of the sulphur in the 

 sulphuric acid from which the matter had been separated 

 by caustic ammonia. It will be seen by further researches 

 what influence this acid has in these trials. 



M. Gahn, of Fahlun, having a proper apparatus, pro- 

 mised to us to undertake the reduction of this substance 

 with more force. If this operation be attended with success, 

 we shall give an account of it hereafter. 



These and the following circumstances have determined 

 us to consider the substance found in cerite as the oxide of 

 a metal hitherto unknown, to which we have given the 

 name of cerium, from the planet Ceres discovered by Piazzi. 



Metltad 



