﻿Notices respecting New Books. 527 



towards enabling the leader of the expedition to collect information 

 of real importance. All that the resources of modern science 

 and technical skill can do for the explorer in enhancing the 

 value of his observations and researches appears to have received 

 due notice in this remarkable work, and no truly scientific ex- 

 plorer can afford to ignore its existence . 



The general editor is to be congratulated on the successful 

 manner in which he has accomplished an arduous task, and a 

 word of praise is due to the publishers for the excellent way 

 in which their part of the work has been done. 



Die PhysiJc Roger Bacos. Inaugural-Dissertation von Sebastian" 

 Yogl. Erlangen: Junge & Sohn. 1906. Pp. xii + 106. 



To those interested in the history of physics, the present pamphlet, 

 which deals with Roger Bacon and the science of his time, will be 

 very welcome. The result of the author's researches appears to 

 be that Bacon's knowledge of physical science was derived from 

 Greek and Arabic sources, and that although no original contri- 

 butions can be traced to Bacon himself, yet the truly philoso- 

 phical and critical spirit in which he examines the science of his 

 time entitle him to be regarded as a great man. "When it is 

 remembered that during the greater part of his life Bacon was 

 practically deprived of means of experimental research, and that 

 he was thwarted in his aspirations at every turn by his superiors, 

 it is hardly to be wondered at that he failed to enrich the science of 

 his time by any striking original discoveries. 



Cours de Physique cle VEcole Poly technique. Par M. J. Jamiw. 

 Troisieme Supplement, par M. Botjtt, Professeur a la Faculte 

 des Sciences de Paris. Paris : Grauthier-Villars. 190G 

 Pp. vi + 420. 



The rapid developments which have recently been taking place in 

 many branches of physics have rendered it desirable to bring many 

 of the old-established standard treatises on the subject up to date. 

 In the case of M. Jarnin's well-known work, this is being done bv 

 the issue of special supplementary volumes in which an accouut is 

 given of recent advances in physics. The book before us forms 

 the third supplement, and deals with Radiation aud Electricity. 

 Under the head of Radiation, the author deals with the emission 

 of black bodies, the pressure of radiation, the emission of gases, 

 the infra-red spectrum, dispersion, Hertzian waves and wireless 

 telegraphy. The next section of the work is headed " Electricity," 

 and is devoted to the electromagnetic effect of electric convection 

 the experimental study of magnetism, alternating currents, electro- 

 lysis, the ionic theory, and Nernst's theory of electrolytic solution 

 pressure. The concluding section, on " Ionization," deals with 



