556 Scientific Intelligence. 



eluded to try the effect of a high tension spark on carbon dust 

 which is suitably placed in a cavity of one of the electrodes. A 

 current of 300 volts was employed : a side circuit included a con- 

 denser of 60 microfarad capacity with very small resistance and 

 self induction. It was found that the temperature of the singing 

 arc under the condition in which it gives the spark spectrum is 

 much higher than that of the ordinary electric arc and the elec- 

 tric oven. The dust after the operation was carefully washed 

 and treated in various solvents ; finally crystalline forms were 

 obtained of great hardness. The paper contains photographs of 

 these forms, which in the main were made up of two tetrahedrons 

 with curved surfaces. The author suspects that he has obtained 

 diamonds, and hopes to determine this question by further investi- 

 gation.— Ann. der Physik, No. 12, 1909, 369-380. j. t. 



11. Determination of e/m. — Kurt Wolz collects the various 

 determinations* of this ratio and uses Bucherer's method for a new 

 determination. He obtains e/m = 1*7674 X10 7 , while Bucherer 

 obtained e/m = 1'763X10 7 . — Ann. der Physik, No. 12, 1909, 

 pp. 273-288. j. t. 



12. Spectroscopic Astronomiqne / by P. Salet. Pp. viii, 431, 

 with 44 figures and 1 plate. Paris, 1909 (Octave Doin et Fils). — 

 Under the direction of Dr. Toulouse the publication of a scien- 

 tific encyclopedia comprising twenty-nine volumes is projected. 

 As yet only two volumes have appeared, one of which has the 

 author and title indicated above. The subject of astronomical 

 spectroscopy is here presented from all points of view and in as 

 interesting a manner as is consistent with the relatively small 

 size (12°) of the pages. Although the text is somewhat synoptic 

 nevertheless it is fully up to date and contains references to the 

 latest discoveries as published in the scientific journals. At the 

 end of each chapter a bibliographical list of the most important 

 works relating to the topics discussed in the respective chapter is 

 given. The book concludes with an alphabetical index of authors 

 and of subjects together with a systematic table of contents. 

 Unfortunately most of the figures of spectra are somewhat 

 blurred and indistinct. However, on the whole, the volume 

 affords excellent reading matter introductory to a more detailed 

 study of astronomical spectroscopy. h. s. u. 



13. A Text- Book of Physics, Second Edition; edited by A. 

 W. Duff. Pp. xi, 698, with 525 figures and 245 problems. 

 Philadelphia, 1909 (P. Blakiston's Son & Co.). — The revised edi- 

 tion of this work (see vol. xxvii, page 85) differs from the first in 

 the following respects. The chapter on wave motion, which was 

 formerly composed by W. Hallock, has been entirely rewritten 

 by E. P. Lewis. Many of the articles have been changed from 

 large to small type and vice versa. As a result the large print 

 portions of the book now constitute a well-balanced briefer 

 course. A number of the poorer figures have been replaced by 

 much better diagrams. Certain articles now conclude with illus- 

 trative tables of physical constants. At the end of each general 



