498 Scientific Intelligence. 



4. Electro- Analysis • by Edgar F. Smith. 12 mo, pp. 336. 

 Philadelphia; 1907 (D. Blakiston's Son & Co.)— This is the fourth 

 edition, revised and enlarged, with 42 illustrations, of a well 

 known, valuable text-book. The changes in the new edition are 

 far more important than is usual in new revisions, for here is in- 

 cluded an account of recent developments in the subject from 

 the author's laboratory, which are of the greatest importance and 

 interest to analytical chemists. Electrolytic analysis heretofore 

 has dealt chiefly with the determination of a few of the heavy 

 metals, but the range of its applications has been gradually en- 

 larged by the discovery of new applications. Au instance of this 

 kind is the determination of the halogens by collecting them upon 

 a silver-plated anode. Dr. Smith's new work has greatly im- 

 proved and extended this application of electrolysis, and he has 

 shown that rapid and accurate determinations of not only the 

 halogens, but of such anions as the carbonate, ferrocyanide, ferri- 

 cyanide, phosphate and sulphide radicals, can be made readily. 

 These remarkable results have been made possible by an ingenious 

 device whereby the alkali metals, as well as barium and stron- 

 tium, are passed through a layer of mercury into an outer com- 

 partment of the electrolytic cell. This same device has enabled 

 the author to make various separations of metals in an exceed- 

 ingly simple and accurate manner; for example, an alkali metal, 

 or barium or strontium, from calcium, magnesium, etc. These 

 new methods devised by Professor Smiih will certainly find 

 extensive practical applications, and they mark an important 

 epoch in electro-analysis. h. l. w. 



5. Fizeau's Research on the Change of the Azimuth of 

 Polarization due to Movement of the Earth. — The endeavors to 

 discover an effect on optical phenomena due to movements of 

 the earth have led to negative results. Fizeau, however, be- 

 lieved that he had noticed such an effect. He passed a polarized 

 light ray through a series of inclined glass plates and noticed a 

 change in the polarizing angle, as the ray passed in the direction 

 of the earth's movement or in the opposite. Fizeau found a dif- 

 ference in the polarizing angle of 0*024°. Bruce repeated 

 Fizeau's experiments with a different order of apparatus and 

 found an angle change of only - 003°, which is within the limits 

 of error, and Bruce concludes that Fizeau's result must have 

 been due to some other cause than that of the movement of the 

 earth. B. Strasser's has taken up the subject and shows that 

 Fizeau's use of a reflecting mirror to change the direction of the 

 ray of light was faulty. It is important that the source of light 

 should not be changed, but should move with the apparatus. 

 Strasser gives a diagram of his apparatus which shows how this 

 result is accomplished, and his tabulated results show that the 

 Fizeau effect does not exist, and that no experiment shows any 

 effect upon optical phenomena due to movement of the earth. — 

 Ann. der Physik, No. 11, 1907, pp. 137-144. J. t. 



