EXPERIMENTS ON CERITE. J 05 



focal point therefore will be a collection of cooled rays of light, 

 which muft necelfarily occafion an effect on the thermometer, 

 the reverfe of that of the former experiment. That light is a 

 body capable of being united with caloric, and that heated or 

 cooled light mould thus be reflected and occafion all the phe- 

 nomena of Mr. Leflie's and of M. Picket's experiments, ap T 

 pears to be much more probable, than that this calorific and 

 frigoriiic fluid {hould be the ambient air, or that cold, as a 

 body, (hould be reflected from mirrors in fuch a manner as 

 light is perhaps only capable of being reflected. Were the 

 experiments Co made that no light ftiould be in the room, and 

 pnly a fmall confined portion of light ufed to examine the 

 thermometer^ thefe conjectures would be put to the trial, and 

 I truft the myftery would be removed. 



Sir, your's, 



J. P* 



VIII. 



Experiments on a Mineral formerly called falfe Tungfiein, now 

 Cerite, in which a new Metal has been found.* 



R. Klaproth, about eight months ago, fays Mr. Vauquelin, Klaproth fup- 



fent me word, that he had difcovered in the tungftein of Baftnas P?f ed he had 



lt ,. , . , r i -i difcovered a new 



a new earth, to which he gave (he name ot ochroit, on account earth in the 



of the red colour it acquired by calcination. MetTrs. Hifinger fa,fe tungfteinj 



and Berzelius, hearing this, wrote to Mr. V. claiming the Hifinger and 



priority of difcovery, but affirming at the fame time, that what ^^ l hxxsanmv 



they had found was a new metal. Thefe gentlemen afterward 



fent Mr. V. fpecimens of the mineral, which he analyfed in 



company wilh two experienced practical chemifts, Me/Trs. 



Taifaert and Bergman. The following were the refults of their 



analytis : 



The pure cerite f is femitranfparent, wilh a flight rofy tinge, Characters of 



pure cerite. 



* Abridged from a paper by Vauquelin in the Annalesde Chimie, 

 Vol. LIV. p. 28, and another by Mcffrs. Hifinger and Berzelius in 

 van Mons's Journal de Chimie, VoL VI. p. 142. — C. 



•\ Meffrs. H. and B. have given to the metal the name of cerion 

 or cerium, from the new planet Ceres, and to the mineral in which 

 they difcovered it that of cerite, 



or 



