244 Scientific Intelligence. 



sand, and by a long series of fractionations involving some 3000 

 crystallizations, they obtained several fractions of constant prop- 

 erties and atomic weight, apparently consisting of pure europeum. 

 The amounts obtained indicated that the monazite sand contained 

 about two hundred-thousandths of europeum oxide. The sul- 

 phate has a scarcely visible rose tint, while the oxide prepared at 

 a low temperature is practically white, although when intensely 

 ignited it is distinctly rose-colored. Closely agreeing atomic 

 weight determinations made with several different fractions gave 

 151 'TO as the result, which the authors believe to be true within 

 •06. Demarcay had given the atomic weight as about 151. — 

 Comptes JRendus, cxxxviii, 628. h. l. w. 



4. The Use of Caleium Carbide as an Explosive in Mining. — 

 Gttedras has described a method of utilizing the explosive force 

 of acetylene for mining purposes. A sheet-iron cylinder is used 

 as a cartridge. At its bottom are placed about 50 g. of granu- 

 lated calcium carbide, and above this in a separate compartment 

 is a sufficient amount of water to react with the carbide. There 

 is also an air-chamber containing an electric fuse. The cartridge 

 is placed in the hole to be exploded, the latter is closed with a 

 wooden plug, and an iron rod attached to cartridge for the pur- 

 pose of piercing the water compartment is struck, thus liberating 

 the acetylene. After this has been disengaged for about five 

 minutes, the mixture of air and acetylene is exploded. The 

 explosion causes the rocks to fly about much less than would be 

 expected, but they are thoroughly broken up. — Comptes Jiendus, 

 cxxxix, 1225. h. l. w. 



5. Silicon-fluoroform. — The silicon compound, SiHCl 3 , silicon- 

 chloroform, is well known, and recently Ruff and Albert, by 

 allowing the compound just mentioned to act upon tin tetraflu- 

 oride or titanium tetrafluoride, have succeeded in obtaining the 

 corresponding fluorine compound. Silicon-fluoroform is a com- 

 bustible gas which liquefies at atmospheric pressure at about 

 — 90° and solidifies at about —110°. It is decomposed by water 

 and alkaline solutions without change of volume, for the hydrogen 

 produced by the decomposition is equal in volume to the original 

 gas, as is evident from the following equations : 



SiHF 3 + 3NaOH + H 2 = Si(OH) 4 + 3NaF + H 2 ; 

 2SiHF 3 + 4H 2 = Si(OH\ 4 + H 3 SiF fi + 2H 2 . 



The preparation of the compound under consideration completes 

 the series SiHF 3 , SiHCl 3 , SiHBr 3 , and SiHI a of analogous halogen 

 compounds. — Berichte, xxxviii, 53. h. l. w. 



6. Double Cyanides of Copper. — A considerable number of 

 these double salts has been prepared and studied by Grossmann 

 and von dee Forst. They are all cuprous salts, and contain 

 lithium, sodium, potassium, rubidium, caesium, as well as ammo- 

 nium, calcium, strontium, and barium. Five different types of 

 double salts were noticed ; for instance, omitting water of crys- 

 tallization, I. KCu 2 (CN) 3 , II. Rb a Cu,(CN) 6 , III. KCu(CN) 2 , IV. 



