346 Scientific Intelligence. 



metric crystals, the silver is deposited as crystalline chloride, 

 while the copper gives red crystals of artificial cuprite, Cu a O. 

 Covered platinum vessels are only slightly attacked by the fusions, 

 and porcelain crucibles resist the action for many hours. Among 

 the compounds prepared were crystallized magnesioferrite, 

 MgFe 2 4 and products intermediate between this and magnetite, 

 FeFe Q 4 , well crystallized magnesium orthoborate, Mg 3 B 2 6 , and 

 magnesium uranate, Mg 3 TJ 2 9 . Cerium dioxide was crystallized 

 by using the sulphate in the magnesium chloride fusion. The 

 authors regard this as one of the most beautiful substances of 

 inorganic chemistry, as it forms colorless cubic or octahedral crys- 

 tals which are very hard, resembling diamond in brilliancy and 

 luster, and having a refractive index above 1*9. By the use of a 

 small proportion of praseodidymium sulphate mixed with the 

 cerium sulphate, reddish yellow to deep red crystals were obtained. 

 Zirconium dioxide also was obtained in the form of white tetrag- 

 onal crystals. The rare earths, used as sulphates or oxides, gave 

 well crystallized oxychlorides, for instance ErOCl was the erbium 

 compound. The authors have studied the absorption spectra of a 

 number of these products. — Berichte, xlvii, 238. h. l. w. 



2. Carbon Sulphide- Telluride and Carbon Sulphide- Selenide. 

 — Alfred Stock, P. Praetorius, and E. Willfkoth have pre- 

 pared the compounds CSTe and CSSe by passing an electric arc 

 under cooled carbon disulphide between a cathode of tellurium or 

 selenium and an anode of graphite. The tellurium compound is 

 very unstable and difficult to purify. It is decomposed by light 

 and exists only at low temperatures. It was purified by distilling 

 in a high vacuum at —35° C. and condensing at — 80° C. At low 

 temperatures it is a yellowish-red solid which melts at —54° C. 

 to a brilliant red liquid, and this becomes blood-red at room 

 temperature, then turns black and soon decomposes completely. 

 It has a garlic-like odor. The selenium compound is much more 

 stable than the other. At room temperature it is a liquid of 

 intense yellow color. Its melting point is — 85° C. and the boil- 

 ing point 84° C. It has an irritating garlic-like odor. It is 

 decomposed by light and by long standing at room temperature. 

 At higher temperatures it decomposes more rapidly, forming car- 

 bon disulphide, carbon and selenium. In the study of both the 

 tellurium and selenium compounds careful search was made for 

 the presence of the possible compounds CTe 2 and CSe 2 , but no 

 evidence of their formation could be found. — Berichte, xlvii, 131, 

 144. h. l. w. 



3. Double Bromides of Gold. — A. Gutbier and J. Huber 

 have prepared and described about eighty double salts of AuBr 3 

 with other bromides, most of which are bromides of organic bases 

 derived from ammonia, but they include the potassium, rubidium 

 and caesium salts, KAuBr 4 , RbAuBr 4 and CsAuBr 4 , the last two 

 of which were described in this Journal by Wells and Wheeler 

 in 1892. Examples of the organic base compounds analogous to 

 the ammonium salts, NH 4 AuBr 4 , are the monomethyl ammonium 



