382 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Oxysulphides of Zirconium and Thorium.— In attempting 

 to prepare sulphides of these metals by heating the sulphates 

 in a stream of hydrogen sulphide, Otto Hatjser has found 

 that sulphides could not be prepared in this way, but that well 

 characterized, perfectly pure oxysulphides corresponding to the 

 formulas ZrOS and ThOS were readily produced. The prepar- 

 ation of the compounds succeeds well only when the sulphides are 

 thoroughly dry. For this purpose they were heated in a stream 

 of dry air at 380-400°. Then they were heated in a, combustion 

 tube to a moderate red heat in a rapid stream of hydrogen sul- 

 phide. A change of color from pure white to yellowish brown 

 indicated a chemical action, while the weights of the resulting 

 products, and analyses of them, corresponded closely to the com- 

 positions required by the formulas. The oxysulphides, particu- 

 larly the zirconium compound, are inclined to ignite spontane- 

 ously when exposed to the air, unless they are allowed to remain 

 in the hydrogen sulphide for some time after cooling. The 

 formation of these compounds is of considerable theoretical inter- 

 est on account of the existence also of COS, with carbon, the 

 typical element of their group. Their formation indicates also 

 that one of the S0 4 groups in the sulphates, Zr(S0 4 ) 2 and Th(S0 4 ) o 

 is more firmly combined than the others, at least at high temper- 

 atures. — Zeitschr. f. anorgan. Chem., liii, 74. h. l. w. 



2. New Method of Preparing Titanium Tetrachloride. — A con- 

 venient method for preparing titanium tetrachloride on a rather 

 large scale is described by Vigouroux and Arrivant. They make 

 use of commercial f erro-titanium, which is now manufactured with a 

 contents of above 55 per cent of titanium. The direct treatment 

 of this material with chlorine gas in a heated porcelain tube 

 gives ferric and titanium chlorides, which may be separ- 

 ated to a great extent by their different volatility, but in this 

 procedure the apparatus soon becomes clogged by the conden- 

 sation of the iron compound. They recommend, therefore, the 

 elimination of the greater part of the iron as a preliminary step 

 by treating the powdered ferro-titanium with dilute hydrochloric 

 acid as long as it reacts. A heavy residue very rich in titanium 

 is thus obtained, which is used as before in the preparation of 

 the tetrachloride. The product is collected in a cooled glass 

 condenser. It is always colored by ferric chloride, but the latter 

 being very insoluble in the liquid can be almost completely 

 removed by simple filtration. Fractional distillation then gives 

 a completely pure product, boiling at 136°, free from chlorides of 

 iron and silicon, entirely colorless, and not fuming in the air. — 

 Comptes JRendus, cxliv, 485. h. l. w. 



