6 P. T. Cleve, 



Oxalic acid gives in neutral or slightly acid solutions a volumi- 

 nous, white, and caseous precipitate which soon becomes pulverulent 

 and crystalline. It is soluble in boiling nitric acid. 



Alkaline oxalates give white, non-crystalline precipitates of double 

 oxalates of samaria with oxalates of alkalis. These precipitates are 

 finely divided and not easy to wash. 



Acetate of sodium gives on boiling with dilute solutions of samaria 

 no precipitate. 



Hyposulphite of sodium produces on boiling with salts of sama- 

 rium no precipitate. 



Ferrocyanide of jjotash gives with salts of samarium a yellowish 

 non-crystalline precipitate of ferrocyanide of samarium and potassium. 



Tartaric acid gives with salts of samarium a white, voluminous 

 precipitate, soluble in ammonia. The ammonical solutions of the tartrate 

 deposit after some time at the ordinary temperature, and immediately on 

 heating, a white powder. v 



Formiate of ammonia gives with concentrated solutions of salts 

 of samarium, especial}^ on evaporating, a white powder of little soluble 

 formiate of samarium. 



Borax and microcosmic salt give with samaria colourless beads. 



Peroxide of samarium. 



If basic nitrate of samarium be heated to incipient redness in a 

 current of dry oxygen as long as red vapours are given off, an oxide 

 remains which has a stronger yellow tint than the oxide of samarium. 

 The loss on heating to a white heat was found in two experiments to 

 amount to 1.35 and 2.81 percent. When dissolved in a solution of a 

 known weight of ammonio-ferrous sulphate mixed with sulfuric acid it 

 did not oxidise more of the ferrous salt than corresponds to O.i percent 

 of oxygen. It seems then highly improbable that a peroxide of samarium 

 could be obtained in the manner described. 



If peroxide of hydrogen (2 percent) be added to a solution of a 

 samarium salt, no visible change occurs, but on adding ammonia a gela- 

 tinous precipitate, perfectly resembling the hydroxyde of samarium, is 

 produced. After a short while oxygen it given off in numerous small 

 bubbles. After washing, one portion of this precipitate, suspended 

 in the liquid, was mixed with a known quantity of ammonio-ferrous 

 sulphate. Ferric hydroxide was immediately thrown down. After adding 



