NATURE 



457 



THURSDAY, OCTOBER 13, 1910. 



THE HISTORY OF PHYSICS. 

 Geschichtstafcli! dcr Pliysik. By Prof. Felix Auerbach. 

 Pp. V+150. (Leipzig: J. .\mbr. Barth, 1910.) 

 4 nik. 



PROF. AUERB.VCH has embodied in this little 

 book of 150 pagfes upon the chief discoveries in 

 phj'sics the result of notes made during many years 

 for his personal use, in preparation for lectures. It 

 consists of three parts : part i. (no pages) is a chrono- 

 logical list of the main steps in the development of 

 physics, with the year and the name of the discoverer, 

 but without citing either the authority or the reference 

 by which the discovery is fixed, and extending down 

 to the year 1900. Part ii. (17 pages), a list of selected 

 works, monographs, treatises, and text-books, with 

 their authors, also to the year igoo. Part iii. (5 pages) 

 is a selected list of leading physicists, except those 

 still living, with their years of birth and death. There 

 is also an alphabetical index of names. 



Doubtless such a list will be found convenient for 

 reference- -much more convenient, for example, than 

 Darmstaedter's recent " Handbuch zur Geschichte der 

 Naturwissenschaften und der Technik," which is a 

 more ambitious work It also covers the ground 

 much more fully than Prof. Lehfeldt's list published 

 in 1894 by the Physical Society. 



.■\ good idea of its nature and scope will be gathered 

 by the following selection of the entries about the suc- 

 cessive steps in photography. 

 1311, Camera obscura ; Levi ben Gerson. 

 1505, Improved camera obscura; Lionardo da Vinci. 

 1556, Blackening of silver chloride by sunlight ; 



Fabricius. 

 1558, Improved camera obscura ; Porta. 

 1728, Action of light on silver compounds; J. H. 



Schulze. 

 1757, Copying of silhouettes on silver chloride paper; 



Beccaria. 

 1777, Photochemical reduction of silver; .Scheele. 

 1777, Violet rays are photographicallv most active; 

 Scheele. 

 Colour sensitiveness of the silver compounds; 



Senebier. 

 The strongest chemical action lies in the ultra- 

 violet ; Ritter. 

 1S02, Production of light-images on silver chloride 



paper in the camera obscura ; Daw. 

 1S02, Photographic silver nitrate silhouettes; ^^'edgc- 



wood. 

 iSio, Photochemical production of colours bv coloured 



illumination ; Seebeck. 

 1816, First permanent and printable photographic 



plates ; Xiepce. 

 1826, Discovery of silver bromide and its sensitiveness 



to light; Balard. 

 1833, Invention of the actinomcter; Herschel. 

 1837, Production of the frrst plates with silver iodide, 

 and developed by mercury vapour ; Daguerre. 

 183S, .\chromatic landscape-lens ; Chevalier. 

 NO. 2137, VOL. 84] 



17S2, 

 iSoi, 



1839, Production of the first negatives copyable upon 



paper ; Talbot. 



1840, Foundation of microphotography ; Donne. 

 1840, Portrait-objective for photography; Petzval. 

 1842, F'irst useful photographs of the solar spectrum; 



E. Becquerel and Draper. 

 1842, Printing-out process with iron salts; Herschel. 

 1S43, Discovery of gold-toning of photograms ; Fizeau. 

 1847, First photographs on albuminised plates; Niepce 



de St. Victor. 



1850, Introduction of gelatine into photography; 



Poitevin. 



185 1, Wet collodion process for photography ; Archer. 



1852, Chrome-gelatine process for photography; 



Talbot. 



&c., &c., &c. 



The subsequent steps are narrated in similar detail ; 

 but, strangely enough, 'the name of Sir Joseph Swan 

 is entirely omitted from the list. Similar lists might 

 be adduced in every branch of physics. As might be 

 expected from Prof. Auerbach, the list in acoustics is 

 particularly complete, while those in optics and in 

 magnetism are scarcely less so. 



The omission of all references to authorities renders 

 criticism difficult ; because the critic, even where he is 

 fairly certain that some error exists, has no means 

 of learning what the compiler of the list relies upon 

 for his statement. Thus the author credits Wilcke, in 

 1757, with the introduction of the conception of electric 

 resistance; he attributes to Scoresby, in 1827, the dis- 

 coverv of the destruction of magnetism by glowing 

 heat; he credits to Hankel, in 1848, the suggestion 

 of the hot-wire galvanometer. One would wish to 

 know the authorities for these statements. There are 

 several inexplicable omissions : Du Bois Reymond's 

 discovery of non-polarisable electrodes is not men- 

 tioned ; Shelford Bidwell and George F. FitzGerald 

 are unknown to the author as having achieved any- 

 thing in physics; Barrett's discovery of recalescence 

 is ignored, as is Osmond's work in the same field. 

 Earnshaw's discovery of the dependence of the velocity 

 of sound on its intensity is unnoticed. Lord Kelvin's 

 publication in 1855 of the doctrine of available energy 

 is not referred to. Osborne Reynolds's work on 

 dilatancv is not mentioned. The foundation of crystal- 

 lometry'is attributed to Weiss in 1813; all reference 

 to the work in that direction of Wollaston, of Haiiy, 

 and even of Steno being omitted! In several cases 

 the dates need revision. Thus, Maxwell's electromag- 

 netic theory of light is given as 187 1, several years too 

 late. A reference to Dr. Gilbert, who died in 1603, is 

 given as 1630. The first research to register the curves 

 of alternating electric currents is attributed to Colley 

 in 1885 ; Joubert has dropped out, even from the index. 

 .•\itken's classical observations on dust nuclei are not 

 recorded. Lord Kelvin's mariner's compass is dated 

 back to 1868, though only patented in 1876. Foucault's 

 use of gas retort carbon for electric light pencils 

 certainly dates back before 1S50; but here it is given 

 as 1866.' These blemishes can easily be removed when 

 a second edition is called for— as it ought to be before 

 long. 



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