Chemistry and Physics. 461 



as well as nitryl fluoride, N0 2 F, which has been prepared by 

 Moisson, but from the latter it differs in its density, in reacting 

 readily with iodine to form iodine pentafluoride, and in reacting 

 with water to form nitrous acid instead of nitric acid. — Zeitschr. 

 Anorgan. Chem., xlvii, 190. ■ h. l. w. 



4. The Atomic Weight of Strontium. — About ten years ago 

 T. W. Richards determined the atomic weight of strontium by 

 means of a comparison of the bromide with silver. He now pub- 

 lishes the results of a comparison of the chloride with silver, 

 made several years ago, but not published at the time on account 

 of a discrepancy in the results due to an unknown cause. This 

 discrepancy has been explained by the recent revision of the rela- 

 tion between silver and chlorine made by Richards and Wells, 

 and it is found that the averages of the two series of determina- 

 tions agree with remarkable closeness wben the correction in the 

 atomic weight of chlorine is made ; thus : 



From SrBr 2 , Sr = 87*663 

 From SrCl 2 , Sr '== 87'661 



These results are based on silver as 107*930, but Richards 

 remarks that this number is probably not exact in comparison with 

 oxygen as 16, and that the result will require modification when 

 the true atomic weight of silver has been determined. — Zeitschr. 

 Anorgan. Chem., xlvii, 145. . h. l. w. 



5. Qualitative Analysis; by E. H. S. Bailey and H. P. 

 Cady. 8vo, pp. 278. Philadelphia, 1905, P. Blakiston's Son & 

 Co. — This book is interesting in being based upon the applica- 

 tion of the theory of electrolytic dissociation and the law of mass 

 action ; but, how T ever important these principles may be con- 

 sidered in connection with teaching the subject, it appears that 

 the extent to which they are carried in this case often causes a 

 loss of clearness and conciseness as far as qualitative analysis 

 is concerned. It may be mentioned that the book is not as large 

 as its pages would indicate, for nearly half of them are left blank 

 for use in keeping notes. h. l. w. 



6. Charging Effect of Hontgen Hays.— The ionizing effect of 

 these rays has been apparently fully proved, and there is a satis- 

 factory agreement in the results of observers. This is not, how- 

 ever, true in regard to the question whether the rays give various 

 bodies upon which they impinge electric charges. The subject 

 has been investigated by Karl Haun, whose results support the 

 contention of Prof. J. J. Thomson, that the rays give a positive 

 charge to bodies. His results are summed up as follows : 



(1) All bodies upon which the rays directly impinge are 

 charged positively. 



(2) Very thin sheets of metals are charged more strongly than 

 thick sheets, and the difference is greater the shorter the exposure 

 to the rays. 



Am. Jour. Sci. — Fourth Series, Yol. XX, No. 120. — December, 1905. 

 32 



