Chemistry and Physics. 155 



Experiments by Goldschmidt have greatly improved the earlier 

 processes, by showing that it is not necessary to heat the crucible 

 containing the mixture, from the outside, as in a furnace. It is 

 quite sufficient to inflame this mixture at a single point, from 

 which the action spreads more or less quickly throughout the 

 mass. The ignition may be effected by means of a piece of mag- 

 nesium wire inserted in the mass and lighted by a match. For 

 mixtures of higher igniting points, a primer made by mixing 

 aluminum powder with a substance easily giving up oxygen, such 

 as lead or manganese peroxide, lead or copper oxide, may be 

 placed on the mixture and this inflamed by the magnesium wire. 

 Since the temperature of the reaction is intense, it is best to line 

 the crucible with a refractory material such as magnesia or 

 alumina, or in some cases the oxide of the metal that is to be 

 reduced. The process may be modified by igniting first a small 

 quantity of the mixture in the crucible, and then adding addi- 

 tional portions from time to time. The metals thus obtained are 

 free from carbon and from carbide, and from aluminum also if the 

 oxide is present in excess. In the case of chromium, the tem- 

 perature reached was found approximately to be 3000°. The 

 fused chromium thus prepared is permanent even in the air of the 

 laboratory, behaving like a noble metal. Fused manganese 

 resembles bismuth, showing surface colors. By this process, 

 alloys of iron with 20 to 25 per cent of boron and with 40 per 

 cent of titanium have been prepared ; and also copper containing 

 10 per cent of chromium. An alloy of lead and barium decom- 

 poses water. Sulphides may be reduced in this way and at a 

 lower temperature. The resulting slag when oxides are used is 

 fused alumina, so hard as scarcely to be scratched by the diamond. 

 In preparing chromium, minute transparent red crystals, resem- 

 bling rubies, are found in it. — Liebigh Annalen, ccci, 19, June, 



1898. G. F. B. 



3. On the Electrolytic Preparation of Beryllium. — It has been 

 shown by Lebeau that beryllium fluoride, while a non-conductor 

 of electricity when fused, becomes a conductor and an electrolyte 

 when mixed with an alkali fluoride. Two beryllium-sodium 

 fluorides, BeF(NaF) 2 and BeF . NaF, are available for this pur- 

 pose. They are most easily prepared by dissolving beryllium 

 hydrate and sodium carbonate, in the required proportions, in 

 hydrogen fluoride and evaporating. The first of these double 

 chlorides fuses at about 350° and the other at about redness. The 

 salt to be reduced is melted in a nickel crucible, acting as the 

 cathode, a rod of graphitic carbon serving as the anode. As 

 soon as the current passes, the external source of heat is with- 

 drawn, the temperature, which should not be allowed to rise 

 above a low red heat, being thereafter maintained electrically. 

 A current of 6 to 7 amperes is required, at an electromotive 

 force of 30 to 40 volts ; the metal separating in the crystalline 

 form. If the electrolysis is conducted in a carbon crucible, 

 which contains the other metal in the fused state, and which 



