CHEMICAL SCIENCE. 173 



haved in several respects differently towards reagents from one of iron 

 only. Subsequently, in an examination of the chrome-iron of Roros, 

 he found that the peroxide of iron separated from it behaved like 

 that in the first-named solution. This, upon a careful and lengthened 

 examination, was found to be owing to the presence of the substance 

 which has been denominated Aridium. M. Ullgren has obtained it 

 in the form of a sulphate of the peroxide in small crystals, and also 

 as a lower oxide. These oxides show considerable analogy to those 

 of iron, but may be distinguished from it by various reactions. A 

 solution of the peroxide of aridium gives a dark blue precipitate with 

 ferrocyanide of potassium ; but an excess of this precipitant changes 

 the color into a dirty bluish-green. It dissolves in hydrochloric acid 

 without disengagement of chlorine, and furnishes, on evaporation at 

 a gentle Stot, a lemon-colored deliquescent residue, which cannot 

 be made to crystallize. It differs in this respect from the oxides of 

 iron and cerium. With carbonate of soda it gives a light brownish- 

 yellow precipitate, with a yellow solution ; peroxide of iron, on the 

 contrary, gives a brownish-red precipitate, which also dissolves with 

 a red color. When hydrosulphuric acid was passed through a solu- 

 tion of the metal, the oxide was reduced to protoxide. After expel- 

 ling the excess of hydrosulphuric acid, it \vas precipitated of a gray- 

 ish-white color by ammonia ; but this precipitate at once became a 

 light brown, without passing from green into brown, as in the protox- 

 ide of iron. Before the blowpipe, oxide of aridium gives, with borax, 

 on platinum wire, in the outer flame, a yellow bead, which becomes 

 colorless on cooling with small quantities. In larger quantities this 

 bead is of a brownish-red ; on cooling, yellow and opalescent. In the 

 inner flame the bead is colored of a light green by small quantities, 

 and becomes colorless on cooling ; with a large quantity the bead is 

 of a beautiful green while hot, but the purity of the color decreases 

 as it cools. Metallic aridium has not yet been obtained. London 

 Chemist, Sept. 



TITANIUM. 



IT is well known that Prof. Wohler, of Germany, has within a 

 recent period ascertained that the beautiful copper-colored crystals of 

 titanium, so often observed in blast-iron furnaces, are not, as has been 

 generally believed, simple bodies, but compounds, made up of the 

 metal titanium and that most unstable of all bodies, nitrogen. The 

 following additional particulars respecting this compound have been 

 communicated by Prof. Wohler to a society in Gottingen : The crys- 

 tals are composed of cyanide of titanium, mixed with nitride of tita- 

 nium, and contain in 100 parts, titanium 78.00, nitrogen 18.1, car- 

 bon 3.89; that is, they consist of cyanide of titanium 16.21, nitride 

 of titanium 83.72. When these crystals are heated in dry chlorine 

 gas, liquid chloride of titanium is produced, and at the same time 

 a crystalline volatile yellow substance sublimes in considerable quan- 

 tities. This latter product is a compound of chloride of titanium with 

 chloride of cyanogen. At the end of the operation, about' one per 



15* 



