Chemistry and Physics. 245 



Na 2 Cu(CN) 3 , V. K 3 Cu(CN) 4 . The salts of type III were ob- 

 tained in the largest number. It may be mentioned that all of 

 these types occur among the known cuprous double chlorides. — 

 Zeitschr. anorg. Chem., xliii, 94. h. l. w. 



7. An Occurrence of Radium and Radio-active Earths. — F. 

 Giesel has found that mud from Fango and soil from Capri 

 possess an activity of about one one-thousandth of that of pitch- 

 blende, and that it is possible to extract radio-active products 

 from them by chemical methods. For instance, from 40 kg. of 

 the Capri soil about half a gram of barium bromide was extracted, 

 which showed distinct spontaneous phosphorescence upon dehy- 

 dration. In neither of the materials could uranium be detected. — 

 Rerichte, xxxviii, 132. h. l. w. 



8. JV-Rays. — E. Gehrcke describes at length certain halluci- 

 nations which might arise in the investigation of the so-called 

 N-rays. He finds that any object, the forefinger for instance, 

 moved to and fro behind a phosphorescent screen produced a 

 change in the light of the screen. The effect is not produced if 

 an independent observer moves the object ; and it is therefore a 

 psychological one. The author believes that the phenomenon is 

 analogous to many which arise at the extreme limit of vision. 

 For instance one often believes that he sees a faint image while 

 developing a photographic plate when no such image really exists. 

 The author does not attempt to explain the photographs obtained 

 by Blondlot and he remarks that in whatever way the phenomena 

 of N-rays may be explained, Blondlot has rendered a service in 

 calling attention to interesting phenomena. — Physikalische Zeit- 

 schrift, No. 1, Jan. 1, 1905, p. 7-8. j. t. 



9. Photography of JV-rays. — G. Weiss and L. Bull have 

 failed to obtain such registration, and remark that Blondlot now 

 concludes that the rays increase or affect visibility and not lumi- 

 nosity. — Comptes Rendus, cxxxix, Dec. 12, 1904, pp. 1028-1029. 



J. T. 



10. Spectra of Electric Discharges in Cooled Ceissler Tubes. — 

 E. Goldstein describes the distribution of light and the spectra 

 produced by suddenly immersing Geissler tubes in liquid air. 

 The method appears to be of use in obtaining the spectra of 

 metals in great intensity and with sharp lines. It also reveals a 

 difference in the cathode light, according to the kind and nature 

 of the cathode. — Physikalische Zeitschrift, No. 1, Jan. 1, 1905, 

 pp. 14-17. J. t. 



11. The Dependence of the Ultra -Red Spectrum of Carbonic 

 Acid upon Pressure. — Clemens Schaefer concludes from his 

 investigation on this subject that Arrhenius' theory in regard to 

 the ice age is erroneous. The latter concluded from his figures 

 that a diminution of the amount of carbonic acid in the earth's 

 atmosphere would lead to a fall of temperature of the earth, and 

 in consequence of diminished absorption there would be an 

 increased radiation of heat from the earth into space. Thus an 

 ice age might have been caused. Schaefer shows that the con- 



