38 New Mineral from Sussex County, New-Jersey. 



lost its colour on cooling. Exposed alone to the blow-pipe, it 

 is infusible. 



To ascertain its nature, it was subjected to the following 

 preliminary process : 



(1) A small portion was separated, and reduced to fine pow- 

 der in a steel dish. In this state it was acted upon with vio- 

 lent effervescence by nitro-muriatic and muriatic acids ; giving 

 with the latter the peculiar smell of hydrogen. The action 

 ceased in about half an hour, leaving a considerable part of 

 the mass undissolved, and but little altered in appearance. 



The muriatic solution being acted upon by tests, showed, 

 among others, the following phenomena : 



(2) With ferrocyanate of potassa a copious blue precipitate. 



(3) With ammonia a precipitate of a rich vermilion red. 



(4) With carbonate of ammonia a reddish white precipi- 

 tate. 



(5) With hydrosulphuret of potassa, a milky appearance, 

 that, subsiding, left a scanty brown precipitate. 



(6) The compounds of cerium being soluble in excess of 

 acid, the nitro-muriatic solution was concentrated until the 

 greater part of the free acid had evaporated, and was then 

 neutralized to the point of nascent precipitation by carbonate 

 of soda. 



(7) A part of the liquor in No. 6 being diluted, crystals 

 of sulphate of soda were thrown in ; these after some hours 

 were dissolved, causing a white precipitate. 



(8) To another portion of the concentrated and neutralized 

 nitro-muriatic solution (6) tartrate of potassa was added, on 

 which a copious white precipitate ensued. 



The suspicion that the substance contained cerium being 

 thus confirmed, it was subjected to a more strict examination, 

 as follows : 



