122 M. Riche on Tungsten and some of its Compounds. 



and sodium is produced. Lithium has the greatest analogy in 

 its chemical relations to magnesium, and it appears to play the 

 same part in the series of alkaline metals as magnesium in the 

 series of alkaline earths. 



M. Riche* has investigated tungsten and some of its com- 

 pounds. He prepared the metal by passing hydrogen over 

 tungsten heated to a very high temperature. At lower tem- 

 peratures bodies containing more or less oxygen are formed. 

 The tungsten thus produced is not melted, or even aggregated; 

 it is in the form of small crystalline grains, which by friction 

 assume a metallic lustre, and scratch glass with great ease ; 

 exposed in a wind-furnace to a temperature sufficient to soften 

 the crucible in which it was contained, it remained solid, and 

 it could only be melted by employing a Bunsen's battery of 

 200 elements. 



Tungsten is acted on by air or even by oxygen only at a high 

 temperature, and is only attacked by chlorine at 300 degrees. 

 It is slowly oxidized by nitric acid to tungstic acid, and by 

 strong sulphuric or hydrochloric acids it is converted first into 

 the oxide of tungsten, and finally into tungstic acid. Heated 

 with iodide of methyle in a closed tube, an organo-metallic 

 compound is produced which has the formula 3(C^ H^) W, 1. 



Riche determined the equivalent of tungsten by passing 

 hydrogen over perfectly pure tungstic acid. He obtained 

 results which fixed the number at 87. This is a little lower 

 than the number usually admitted, and probably arises from 

 the greater purity of the substance used in this case. 



The oxychloride is readily obtained by passing chlorine over 

 a mixture of tungstic acid and powdered charcoal heated to dull 

 redness, and redistilling the product formed in a current of 

 hydrogen. It has the formula W, Cl^ 0, and forms with water 

 tungstic and hydrochloric acids, 



WCP0 + 2H0=W03 + 2HC1. 

 Terchloride of tungsten, W Cl^, is obtained by passing chlorine 

 over metallic tungsten, moisture being carefully excluded. It 

 crystallizes on sublimation in long steel-gray needles which melt 

 at 218 degrees, and the fracture of which presents the appear- 

 ance of iodine. The bichloride W Cl^ is obtained in small 

 quantities by passing hydrogen over the terchloride. Bisul- 

 phide of tungsten is obtained by melting together equal weights 

 of tungstate of potash and sulphur until gentle fusion. On 

 treating the cooled mass with water the bisulphide is left in 

 small acicular crystals of a black colour, which are changed to 

 red by contact with the air. 



* Comptes Rendus, February 4, 1866, 



