164 GADOL1NITE. 



loses its lustre, and becomes slightly blue. It feebly 

 decomposes water at 100. Hydrochloric acid dis- 

 solves it with energy ; concentrated nitric acid con- 

 verts it into a clear brown oxide ; the dilute acid 

 dissolves it. By evaporation a white salt is obtained, 

 which leaves, after calcination, a brown oxide, insolu- 

 ble in nitric acid and in dilute sulphuric acid. Con- 

 centrated sulphuric acid slowly dissolves this oxide, 

 forming a yellow solution, which shows the reactions 

 of eerie salts. Hydrochloric acid dissolves this oxide 

 with disengagement of chlorine, forming a colorless 

 solution. When a globule of cerium is heated by the 

 blowpipe to dull redness, the metal inflames and burns 

 vividly, forming brown oxide; but upon submitting a 

 globule suddenly to a very high temperature, it burns 

 with explosion, sending out bluish sparks. Cerium 

 powder can inflame below 100. 



88. GADOLINITB.* 



YO, CeO, LaO, ErO, CaO, MgO, MnO ; FeO, Fe 2 O 3 , 

 Al a O,,SiO r 



The finely-powdered mineral, dried at 100, is de- 

 composed by digestion, in a porcelain dish, with concen- 

 trated hydrochloric acid, to which some nitric acid has 

 been added, to peroxidize the iron ; the mass is com- 

 pletely dried up, with frequent stirring, in a water-bath, 

 and maintained for some time at that temperature. 



It is then digested with .a little water acidulated 

 with hydrochloric acid, the silica filtered off', washed 

 with hot water, thoroughly dried, ignited and weighed. 



* This rare numeral varies in composition according to the local- 

 ity in which it is found. All specimens contain yttria, oxides of 

 cerium, iron and silica as the ingredients, many, glucina and 

 small quantities of lime, magnesia and manganese. 



