Chemistry and Physics. 389 



5. A Salt of Quadrivalent Antimony. — It has been found by 

 Wells and Metzger that the black, or rather very dark blue, 

 salt, Cs 2 SbCl 6 , which was described by Setterberg in 1882 as 

 crystallizing in short prisms, is really octahedral in form, and 

 that it crystallizes isomorphously with Cs a PbCl a , giving crystals 

 of various shades of green when mixed with this yellow salt. 

 The octahedral form is characteristic of a large number of double 

 chlorides of quadrivalent elements, like K 2 PtCl fi ; hence it is 

 probable that Setterberg's salt contains antimony tetrachloride. 

 Attempts were made to prepare SbCl 4 , or to find some evidence 

 of its existence, but without success. It should be black in color, 

 and the oxide corresponding to it should be black also ; hence it 

 is probable that the well known oxide Sb0 2 , being white, does 

 not correspond to the tetrachloride. — Amer. Chem. Jour., xxvi, 

 268. h. l. w. 



6. A New Method for the Gravimetric Determination of Tel- 

 lurium. — Gutbier has found that hydrazine hydrate and the salts 

 of this base readily precipitate tellurium quantitatively from 

 solutions of all tellurium compounds, and he highly recommends 

 this method for the determination of this element. The precipi- 

 tation is made in a nearly neutral or in a hydrochloric acid solu- 

 tion, and the precipitated metal is made flocculent before filtering 

 by boiling the liquid. It is remarkable to notice that the author 

 recommends weighing the tellurium on a paper filter, since the 

 Gooch-filter is far better adapted for the purpose. The test- 

 analyses given are satisfactory. — Berichte, xxxiv, 2724. h. e. vy\ 



7. Diffusion of Hydrogen through Palladium. — The depend- 

 ence of this diffusion upon pressure of the diffusing gas is the 

 subject of a study by A. Winkelmann. It was found that the 

 quantity of hydrogen which diffuses through glowing palladium 

 is not proportional to the pressure of the hydrogen. With 

 diminishing pressure the quantity of gas is greater than this 

 supposition demands. If one supposes that a dissociation of 

 hydrogen occurs, and that the diffusing quantity is proportional 

 to the pressure of the dissociated molecules, then the facts can 

 be sufficiently explained. It is evident on this supposition that 

 only the atom and not the molecule of hydrogen passes through 

 the glowing palladium. — Ann. der DhysiJc., No. 9, 1901, pp. 104- 

 115. J. t. 



8. Cathode Hays. — The emission theory of these rays appears 

 to be the prevailing one, at least in Germany. W. Seitz has 

 undertaken a study of the questions, what is the action between 

 the emission particles and the material atoms or molecules in case 

 that the latter can be considered at rest in comparison with the 

 great velocity of the rays, whether one has to deal with fric- 

 tional forces or conservative forces, and whether attraction or 

 repulsion is exerted. For the study of these questions there 

 appear to be two ways open : the study of reflection and that 

 of the phenomena presented by the passage of the rays through 

 thin membranes. It was found that the cathode rays are dif- 



