Chemistry and Physics. 557 



4 : 1 



(NH 4 ) 4 SnCl,H,0 (NH 4 ) 4 SnBr 4 .H 2 



K 4 SnCJ 6 .H n O K 4 SnBr 4 .H 2 



(NH 4 ) 4 PbCl 6 .H 2 0. 



These salts are of considerable interest, since they confirm the 

 type made by Poggiale and since they correspond in type to the 

 caesium salts Cs 4 PbCl 6 and Cs 4 PbBr 6 prepared by G. F. Campbell 

 and by P. T. Walden, and described in this Journal, Feb. 1893, 

 They are exceptions to a rule advanced by Professor Remsen 

 requiring that the number of alkaline halide molecules in a 

 double halide shall not exceed in number the halogen atoms of 

 the more negative halide. — Zeitschr. anoryan. Chem., civ, 139. 



H. L. W. 



2. The Production of Liquid Hydrocarbons from Naphthaline. — 

 Naphthaline is one of the large products of the distillation of coal 

 tar, its annual production in Germany being about 80,000 tons. 

 Its chemical applications are limited, so that the greater part of 

 it is used for fuel. Franz Fischer has applied Friedel and 

 Crafts' reaction to this material, using only about 5 per cent of 

 aluminium chloride and heating under pressure with the result 

 that a liquid product amounting to about one-third of the weight 

 of the naphthaline was obtained. Upon refining this by distilla- 

 tion and other treatment, an oil distilling between 150° and 300° 

 C, amounting to about 18 per cent of the original naphthaline, 

 was obtained. It appeared to consist partly of dihydronaphtha- 

 line. It did not burn satisfactorily in an ordinary kerosene lamp 

 as the flame was smoky. Possibly a modified lamp admitting a 

 larger supply of air might use it. — Berichte, xlix, 252. h. l. w. 



3. The Application of Paper Palp as a Filter in Quantitative 

 Analysis.-— §. L. Jodidi and E. H. Kellogg recommend the use 

 of filter paper pulp in a Gooch crucible for filtering and weigh- 

 ing barium sulphate, silver chloride, potassium platinic chloride, 

 and ammonium platinic chloride. They state that results obtained 

 in this way are as accurate as those obtained with "standard filter 

 paper," and that considerable time and labor are saved. Although 

 this article has been published " By permission of the Secretary 

 of Agriculture," the advice does not appear to be good. The use 

 of paper pulp for filtration is already very well known, but proba- 

 bly it has seldom been used in place of asbestos for weighing- 

 precipitates in the Gooch crucible, because it is less satisfactory 

 and much less convenient. The proposed method seems to be a 

 backward step towards the former extensive use of "tared filters," 

 which at present are avoided as far as possible. The proposed 

 operation with barium sulphate, where the pulp is to be burnt by 

 putting the Gooch crucible into a larger platinum crucible, is cer- 

 tainly cumbersome and unsatisfactory. — Pour. Indust. and Eng. 

 Chem., viii, 317. h. l. w. 



4. The Gases of the Atmosphere; by Sir William Ramsay. 

 Fourth Edition, 8vo, pp. 306. London, 1915 (Macmillan & Co., 



