194 Account of Expcrirnenis' 



this subject written in Swedish. M. Limdbon undertook 

 a translation of it, and caused it to be printed in the An- 

 nates de Ckimie*. In this memoir they give a history of 

 the mineral, and point out the places where it is found, and 

 the substances which accompany it : they then give an ac- 

 count of the methods they employed to ascertain the na- 

 ture of it : they give the characters of the new substance it 

 contains, and which they consider as a peculiar metal, to 

 which they give the name of cerium ; a denomination taken 

 from the planet Ceres, discovered by M, Piazzi : they have 

 thence formed that of cerite, to- denote the natural ore of 

 that metal. 



About the end of November, that year, I received, by 

 the care of Messrs. Hisenger and Berzelius, specimens of 

 this fossil ; with an invitation to repeat their experiments, 

 and to determine whether the substance in question ought 

 to be classed with the earths or the metals, 1 charged my- 

 self the more readily with this labour, as it furnished me 

 with an opportunity of subjecting to experiment a new sub- 

 stance, and of pronouncing in regard to the opinion of re- 

 spectable philosophers, whose sole object is truth. 



It will be seen by this memoir that the force of facts has 

 obliged me to adopt the opinion of the Swedish chemists* 

 I must not omit to mention that I have been seconded in 

 my experiments by Messrs. Tassaert and Bergman, both of 

 whom are well versed in practical chemistry .^ 



Physical Properties of Cerite. 



This mineral is of a slight rose colour : it is sufficiently 

 hard to scratch glass : its specific gravity is 45*30, and itS' 

 dust is grayish : it becomes reddish by calcination, and loses 

 twelve per cent. 



There are some varieties which contain martial pyrites,, 

 and which are traversed by veins of green actinote.. 



Preliminary Trials on Cerite, 

 This mineral, when pulverized in a mortar of silex, does- 



not increase in weight, which indicates that its hardness is 



not very great : its dust is of a rust gray colour. 



When exposed to heat in a retort there are obtained some 



drops of water, which are condensed in the neck of the 



vessel. 



The dust of cerite is powerfully attacked by the nitric 



muriatic and nitro -muriatic acids; caloric is developed, and 



• No. 150, Praiiial 30, an 12. 



there 



