Chemistry and Physics. 195 



which indicates occlusion or absorbtion of the rarified gas in the 

 glass walls of the tubes. Eduard Rjecke has studied this 

 soaking in effect in the case of nitrogen. He compares the effect 

 of mere gas absorbtion with the absorbtion induced by the elec- 

 trical discharges and estimates the connection between the 

 strength of current and the resulting diminution of pressure. — 

 Ann. der Phys., No. 15, pp. 1003-1009. j. t. 



10. The N-rays. — Authorities are still divided in regard to the 

 existence of these rays. A. Beoca (Archives d'El Medicale, pp. 

 723-740, Oct. 10, 1904) points out that the observation of these rays 

 is an extremely delicate one ; in his own case it was six weeks 

 before he could see the rays. He submitted himself to an elabo- 

 rate course of training and he gives an account of the best way of 

 studying the rays. He dwells upon the necessity of observing 

 physiological conditions. Thus the eye must be adapted to 

 almost completed darkness or at least to very feeble lights. The 

 observer must be left with his mind free, all instrumental changes 

 being intrusted to another. The effects due to heat must be 

 borne in mind ; for the physiological radiations can be entirely 

 swamped by the heat effects. The two effects can be distin- 

 guished by the slight lagging (up to a few seconds) behind of the 

 effect due to the N-rays, such lag being much greater in the case 

 of the heat effect ; and on the cessation of the action the differ- 

 ence of lag is even greater. The N-ray effect may also be dis- 

 tinguished by the different behavior when viewed normally, at 

 45°, and at grazing incidence. — Science Abstracts, Dec. 27, 1904. 



It is stated in the Revue Scientifique of Nov. 26 that M. 

 d'Arsonval has been able to reproduce the N-rays and to show 

 that they are not due to heat. Mascart is stated to have observed 

 the phenomena with D'Arsonval. — Nature, Dec. 15, 1904. 



J. T. 



11. The Recent Development of Physical Science ; by William 

 Cecil Dampiee, Whetiiam, M.A., F.R.S., Fellow of Trinity 

 College, Cambridge, pp.445, 8vo. Philadelphia, 1904 (P. Blak- 

 iston's Son & Co.). — At a time like the present, when the public in 

 general is more than ever before keenly alive to the progress 

 made in science, it is most useful to have the topics of immediate 

 interest presented in a form so simple and clear that anyone who 

 is well grounded in the fundamental principles can gain a good 

 understanding of what is being done. This is eminently true of 

 the book in hand, which, in a series of eight chapters, gives an 

 admirable presentation of some of the subjects in physics, which 

 are just now of greatest interest and in which progress has been 

 and is being made. The author has a thorough command of his 

 subject, and has also had the advantage of assistance from vari- 

 ous specialists in the different lines. Some of the subjects dealt 

 with in the eight chapters are : the liquefaction of gases, fusion 

 and solidification, solution, electric conduction through gases, 

 radio-activity, atoms and ether. The frontispiece is a representa- 

 tion of the well-known statue of Newton, and portraits of Lord 



