452 Scientific Intelligence. 



Conduction in Gases. B. Walter and R. Pohl have repeated 

 the experiments of Hayn and Wind and do not substantiate 

 them, and find that the wave lengths 0*012 and 0*27/a/a found by 

 these experimenters, if such wave lengths exist, must lie far under 

 0'1/a/a. — Ann. der Physik, No. 4, 1908, pp. 715-724. j. t. 



14. JElectrolitic Rectification of Niobium. — G. Schulze under 

 this head discusses the rectification of alternating currents by 

 various metals, and concludes that the rectification behavior of 

 niobium is similar to that of tantalum, and it appears that scan- 

 dium, lanthanum, yttrium, ytterbium, show rectification quali- 

 ties. — Ann. der Physik, No.'s, 1908, pp. 775-782. j. t. 



15. A Manucd of Practical Physics ; by E. S. Ferry and 

 A. T. Jones, Vol. I, pp. xi, 273 ; London and New York, 1908. 

 (Longmans, Green & Co.) — This volume contains a well-arranged 

 and fairly extensive series of experiments upon fundamental 

 measurements, the properties of matter, and heat. In the list of 

 experiments chosen, it does not differ greatly from other labo- 

 ratory manuals ; but the theory underlying each measurement 

 is given in considerable detail, and the sources of error are care- 

 fully considered, so that the work is really of a more advanced 

 character than some others which apparently cover the same 

 ground. Two other volumes upon Sound and Light and upon 

 Electrical Measurements are in preparation. h. a. b. 



16. La Telegraphie sans Fil / par I. Van Dam. Deuxieme 

 edition. Pp. xiii, 239. Paris et Liege, 1908 (Ch. Beranger). — 

 The first three chapters of this work deal with the elementary 

 theory of the production and propagation of electrical waves 

 with special reference to their application in wireless telegraphy. 

 Succeeding chapters give descriptions of the numerous forms of 

 receivers which are in use, of methods.of syntonization, of special 

 apparatus for measurement and of the arrangements of appara- 

 tus which are characteristic of the various "systems" now in 

 use. Short chapters are included upon undamped waves such 

 as are given by the Poulsen arc, and upon the attempts which 

 have been made to give a determinate direction to the waves. 

 The final chapter gives an account of the legal regulation of 

 wireless telegraphy in various countries and of the international 

 convention of 1906. As a whole the book is interesting and well 

 arranged ; so far as the reviewer can judge it appears to be up 

 to date and should prove a useful compendium of the present 

 state of the art of wireless telegraphy. h. a. b. 



II. Geology. 



1. Shepard on the Underground Waters of Missouri / by 

 A. C. Lane (communicated). — The U. S. Geological Survey has 

 recently issued a Water Supply paper* which attracted my atten- 

 tion, since I had recently cited a St. Louis water as an example of 

 buried seawater.f 



* Water Supply and Irrigation Paper No. 195, Underground Waters of 

 Missouri, their geology and utilization, by Edward M. Shepard. 

 f Science, August 8, 1907, p. 135. 



