262 Scientific Intelligence. 



carry the idea upward as well as downward ; to assume that the 

 planets and fixed stars are atoms of the next higher order, that 

 there are many orders on beyond, so that at the end of ends there 

 would be infinitely large atoms, a conception which is likewise 

 not easy to grasp. — Recueil, xxvii, 418. h. l. w. 



5. Introduction to the Rarer Elements, by Philip E. Brown- 

 ing, 8vo, pp. 200. New York, 1908 (John Wiley & Sons). — 

 This is the second edition, thoroughly revised and considerably 

 enlarged, of a book which first appeared five years ago and is well 

 known to the chemical public. Among the additions found in 

 the new edition is a chapter by Dr. Boltwood, giving an excel- 

 lent and concise account of the Radio-Elements. h. l. w. 



6. Feste Lo sung en und Isomorphismus, by Gitjseppi Bruni. 

 12mo, pp. 127. Leipzig, 1908 (Akademische Verlagsgesell- 

 schaft). — The author of this book has taken an active part in the 

 development of modern views regarding solid solutions. In this 

 volume, he gives an exceedingly clear account of the work that 

 has been done and the results that have been obtained. The first 

 part consists essentially of a lecture delivered at Breslau and this 

 is supplemented with an appendix containing additional notes 

 and references. h. w. f. 



7. The Production of Helium from Uranium. — F. Soddy 

 refers to his previous work on the production of helium from 

 thorium and extends his work by a study of the production of 

 this gas from uranium. He concludes that this gas is produced 

 from uranium with an approximate velocity of 2-10 -12 (year) -1 . 

 That is, out of 1,000,000 kg. of uranium 2 mg. of helium are 

 produced per year. Preliminary results with sylvine give a 

 production velocity of 2*5 X10 -12 (year) -1 . — Physik. Zeitschrift, 

 Jan. 15, 1909, p. 41. j. t. 



8. The Charge and Nature of the a- Particle. — E. Ruth- 

 erford and H. Geiger review the work upon this subject, 

 comparing the charge on the a-particle with that on the hydrogen 

 atom — finding it between 2e and 3e. They compare various 

 methods of determining this charge and discuss the accuracy 

 of different methods of determination. It is maintained that 

 the quantity of helium formed from a gram of radium is 

 5-0xl0 -9ccm per second. The life of radium is 1760 years. — 

 Physik. Zeitschrift, Jan. 15, 1909, pp. 42-46. J. t. 



9. Amount of Water in a Cloud formed by Expansion of 

 Moist Air. — In the celebrated experiments of C. T. R.Wilson and 

 Professor J. J. Thomson — on the determination of the number 

 of ions by means of condensation of vapor — it is assumed that 

 the air is cooled to the full extent by the adiabatic expansion 

 before the drops begin to form. Professor W. B. Morton has 

 investigated the conditions which would result if the expansion 

 and condensation kept pace with each other, the process being a 

 reversible one, and find that Thomson's results and his own 

 differ only by six per cent. The assumption of complete adia- 

 batic cooling of the air does not introduce an error comparable 



