232 Scientific Intelligence. 



found both rubidium and caesium in the bluish-green microcline 

 from Miask in the Ilmen mountains. In order to examine the 

 matter more thoroughly, Vernadsky and Revoutsky have now 

 examined a number of samples of microcline spectroscopically, 

 and have found the following elements present: 



Miask, Russian, K, Na, Rb, Li. 



Arendal, Norway, Ba, K, Na, Rb. 



Pike's Peak, Colorado, K, Na, Rb, Li, Cs. 



Hunttila, Finland, K, Na, Ba, Rb, Li. 



Lojo, Finland, K, Na, Ca, Li (Rb?). 



These results were obtained by heating fragments of the mineral 

 directly before the gas-oxygen blowpipe and observing the 

 spectrum of the flame. The results show that Barbier's view is 

 evidently incorrect. — Comptes Hendus, cli, 13*72. h. l. w. 



4. Preparation of Argon. — G. Claude has found a convenient 

 way to prepare large quantities of argon. As a starting point he 

 uses the oxygen produced by the liquefaction of air, which 

 may be obtained 95 per cent pure, and with argon as its prin-" 

 cipal impurity, amounting to about 3 per cent. This oxygen is, 

 therefore, about three times richer in argon than ordinary air. 

 The oxygen is absorbed by hot copper, and the nitrogen by hot 

 magnesium, only a small amount of the latter being required. 

 A tube of hot copper oxide serves finally to oxidize any hydro- 

 gen that may have been formed from moisture present in the 

 materials employed. — Comptes Hendus, cli, 752. h. l. w. 



5. Die Stellung der neueren Physik zur mechanischen Na.tur- 

 anschauung / von Dr. Max Planck. Pp. 33. Leipzig, 1910 (S. 

 Hirzel). — This pamphlet contains a lecture given before the 

 eighty-second meeting of the German Scientists and Physicians, 

 held in Konigsberg, last September. It deals with the Theory of 

 Relativity and with the philosophical views to which it leads in 

 the minds of many German mathematicians and physicists. To 

 the Anglo-Saxon mind, these views appear to touch the limits 

 of philosophical idealism. Ether and matter, in fact all substance, 

 is apparently discarded, and the physical universe consists of a 

 vacuum mitigated by the presence of the Principle of Least 

 Action, and Maxwell's Equations; the "building stones," of 

 which the physical world is constructed, are no longer material 

 particles but the so-called universal constants : the velocity of 

 light, the charge and mass of the electron, the " elementare Wir- 

 kungsquantum," etc. h. a. b. 



6. History of the Cavendish Laboratory, 1871-1910. Pp. 

 x, 342. London, 1910 (Longmans, Green & Co.). — This volume 

 has been prepared in commemoration of the twenty-fifth anniver- 

 sary of Sir J. J. Thomson's election to the Cavendish Professor- 

 ship of Physics in the University of Cambridge. It is the work 

 of several different authors, each period of the history of the 

 laboratory being treated by one who was intimately connected 

 with it during the time in question. Messrs. Fitzpatrick and 



