Chemistry and Physics. 391 



that the appearance of this new edition requires no comment, 

 except the statement that it contains some important changes 

 and additions. h. l. w. 



6. Emanation of Radium. — Sir William Ramsay from a 

 careful study of this emanation concludes that it behaves like an 

 ordinary gas resembling the gases of the argon family. It is 

 luminous and obeys Boyle's law. A table of wave lengths of its 

 spectrum is given. The gas is probably monatomic with a density 

 of about 80 and an atomic weight of 160. Its electrons cannot 

 be made to penetrate other bodies. The name Exradio is pro- 

 posed for this gas. — Comptes Rendus, June 6, 1904, pp. 1388- 

 1394. j. t. 



1. Emanations — Radiations. — Berthelot suggests that sur- 

 face films of volatile substances may account for many of the 

 observed phenomena of radio-activity. In this connection the 

 smell of metals is significant. — Comptes Rendus, June 20, 1904, 

 pp. 1553-1555. J. t. 



8. Conduction of Electricity through high Vacua. — Hon. R. 

 J. Strctt believes from his experiments that, even in high vacua, 

 there is a loss of electricity from a charged body, in presence of 

 the a-rays, independent of traces of residual gas. A rod of bis- 

 muth was made radio-active by a deposit of radio-tellurium which 

 emitted a-rays only. The rod was attached to an electroscope. 

 The exhaustion was pushed to the degree that no discharge could 

 be forced through a Rontgen tube connected with the apparatus. 

 The leak seemed to be distinct from that which is due to the ordi- 

 nary ionization of gases. The author believes that the leak 

 results from the particles torn off from the bismuth by the issuing 

 a-ray. No details are given in regard to the character of sus- 

 pension of the rod. — Phil. Mag., Aug., 1904, pp. 157-158. J. t. 



9. Negative Ions from Heated Metals and Oxides. — Many 

 observers have studied the formation of positive or negative 

 ions on heated metals. A. Wehnelt has shown that not only 

 metals but a large number of metallic oxides possess the same 

 property and to a much higher degree than the metals. He con- 

 tinues his investigation in this article and sums up his results as 

 follows : 



If platinum foil is covered with the oxides of the earth alkali 

 (Ca, Ba and Sr) the cathode fall of potential is much lessened, from 

 the numerous negative ions which are emitted. It was found at 

 atmospheric pressure that negative ions issued even at a dark red 

 heat from the oxides, while pure platinum held negative ions 

 even at a very high temperature. In a vacuum the oxides and 

 also pure platinum emitted negative ions, the number of which 

 increased with the temperature. With the oxides the number of 

 ions was 1000 times greater than with platinum. Calculation 

 showed that the negative ions per volume-unit of the metallic 

 oxide are 100 times greater than the number of the molecules in 

 the same volume, so that one must assume that to each molecule 

 of the oxide numerous negative ions are combined. The lessen- 



