ACCOUNT OF CERIUM. Xl 



is formed. The alkalies augment it, and give it a clear cho- 

 colate colour. If a larger quantity of alkali is gradually added, 

 the quantity of the precipitate> and the intenfity of its colour 

 are increafed ; in proportion as this addition is made, the pre- 

 cipitate becomes of a reddilh brown, and at length, by expo- 

 fure to the light, gives a turbid, deep green folution. 



With Pruffic Acid. 



(R.) The faturated folutions of cerium are precipitated Pmfiiate of ce- 

 white by the prufilates. The voluminous precipitate has much num * 

 refemblance to filver precipitated by muriate of foda. An ex- 

 cefs of acid readily diflblves this precipitate. 



Oxide of Cerium xvith Sulphurated Hidrogen. 



(S.) At the commencement, the faturated folutions of ce- Hydro-fulphuret 

 rium are precipitated of a brownifh colour by hidro-fulphuret erium * 

 of ammonia ; but if more of this re-agent is added, the precipi- 

 tate is of a deep green. The muriale of cerium alone takes 

 a deep green colour, but if an alkali is added to it, an hidro*. 

 fulphurated combination of muriate of cerium, at a minimum 

 of oxidation, is formed, which is rapidly precipitated of a 

 bright green colour. 



The hidro-fulphurated cerjum, well dried, has a deep green 

 colour, almoft black. It is eafily deftroyed by heat ; put into 

 a crucible, moderately hot, it burns with a yellowifli, phofpho- 

 ric flame, only vifible in the dark. 



Sulphurated Oxide of Cerium, 



(T.) The fulphuret of ammonia gives a fading brown pre- Sulphurated ox - 

 cipitate with the folutions of cerium. This fulphuret, added ide of cerium * 

 in exeefs, gives a precipitate of a grafs green, which becomes 

 bright green by deficcation : it burns with a blue flame and the 

 pure oxide remains. 



The muriate of cerium at a minimum is precipitated white by 

 fulphuret of ammonia. 



Oxide of Cerium xvith Phofphorus. 



(U.) A piece of pure phofphorus was put into a folution Phofphate of ce- 

 of muriate of cerium contained in a clofed veflel, and kept for riuin * 

 leveral days on a flove. The bottom and fides of the veflel 

 were covered with a white precipitate, and the piece of phof- 

 phorus 



