556 Scientific Intelligence. 



Vegetable Physiology, Mineralogical Chemistry, and Radio- 

 activity, h. l. w. 



6. The Progress of Scientific Chemistry in Our Oien Times ; 

 by Sir William A. Tilden. 8vo, pp. 366. London, 1913 

 (Longmans, Green and Co.). — This is the second edition, to 

 which some new matter has been added, including biographical 

 notes, of a somewhat popular discussion of the subject. The 

 book is based on a course of " Lectures to Workingmen " and it 

 gives a clear and excellent discussion of modern chemical princi- 

 ples and the discoveries that have led to their establishment. It 

 is a very suitable book for the use of students of chemistry of all 

 grades, and it will serve as a valuable aid to the chemical lec- 

 turer, h. l. w. 



1. The Synthetic Use of Metals in Organic Chemistry • by 

 Arthur J." Hale. 12mo, pp. 169. Philadelphia, 1914 (P. 

 Blakiston's Son and Co.). — This little book of British origin 

 discusses, as its title indicates, only those reactions of organic 

 chemistry where metals and metallic derivatives have been uti- 

 lized in the development of this branch of chemistry. Important 

 reactions of recognized merit are discussed and illustrated fully 

 by structural equations. A feature of the book is an appendix 

 devoted to simple organic preparations which illustrate various 

 applications of the metals. The general scope of the book, how- 

 ever, is narrow and the treatment of the subject far from com- 

 plete. T. B. J. 



8. Electrical Analogue of the Zeeraan Effect. — Ip a series of 

 four papers by J. Stark and his co-workers, G. Wendt and H. 

 Kirschbaum, an account is given of some new and important phe- 

 nomena exhibited by spectral lines under special conditions. In 

 brief, the general problem was to investigate the effect (if such 

 exists) of electric fields on spectral lines. 



Transverse effect. The apparatus used was ingeniously con- 

 structed as follows. A cylindrical vacuum tube was provided 

 with disc electrodes which were set coaxially and relatively far 

 apart. The cathode was jDerforated in order to allow the canal 

 rays to enter the region of the tube more remote from the anode. 

 In this region a third disc electrode was fixed parallel to the 

 cathode at a distance of 1-1 or 2-6 mms from the cathode. The 

 third disc and the cathode were joined respectively to the neg- 

 ative and positive poles of a suitable source of constant potential. 

 Since the perforated cathode and the neighboring disc were close 

 together, very large potential gradients could be readily estab- 

 lished between the electrodes. The pressure of the gas in the tube 

 was regulated to make the cathode dark s]3ace 5 to 10 cms. long and 

 therefore to amply surround the perforated cathode and the adja- 

 cent negative disc. When the tube proper was not excited no dis- 

 charge took place betw T een the perforated cathode and the auxili- 

 ary cathode up to, and exceeding, potential gradients of 50,000 

 volts per cm. When all three electrodes were simultaneously in 

 action the canal rays ionized the gas between the juxtaposed discs 



