SCIENCE 



Feidat, February 4, 1910 



CONTENTS 

 The American Chemical Society: — 



Some Chemistry of Light: De. W. R. 

 Whitney 161 



The American Association for the Advance- 

 ment of Science: — 



Racial Differences in Mental Traits: Pro- 



FESSOB R. S. WOODWORTH 171 



Scientific Notes amd News 186 



University and Educational Neios 189 



Discussion and Correspondence : — 



The Oreen Bug and its Natural Enemies: 

 S. J. Hunter. Gametogenesis of the Saw- 

 fly Nematus Bibesii: Leonard Doncaster. 

 Mountain and Valley Winds in the Cana- 

 dian Selkirks : B. M. Vabnet 190 



Scientific Books: — 

 Kahlenberg's Outlines of Chemistry: Pro- 

 fessor Gilbert N. Lewis. Investigations 

 of Muscid LarvcB Entoparasitio on Arthro- 

 pods: C. H. T. TowNSEND. The Autobiog- 

 raphy of Sir Henry Morton Stanley: Pro- 

 fessor William Libbet 193 



Progress of Paleontological Research by the 

 Carnegie Institute 197 



Optically Active Substances containing no 

 Asymmetric Atom: Professor J. Bishop 

 Tingle 198 



Incomes of College Graduates Ten Years after 

 Graduation: Herbert Adolphus Miller . . 199 



Societies and Academies: — 



The Microscopical Society of Illinois: Al- 

 bert MoCalla 200 



MSS. intended for publication and books, etc., Intended for 

 review should be sent to the Editor of Science, Garrison-on- 

 Hudson, N. Y. 



^ SOME CBEMISTBY OF LIGHT ^ 

 From the dawn of history, chemistry has 

 had much to do with the production of 

 artificial light, and I wish now to recall to 

 your minds a few illustrations. I will not 

 burden your ears with a long story on 

 physics or mechanics of light, but intend 

 treating the subject of artificial light so as 

 to show you that it has always been largely 

 a subject for chemical investigation. I 

 want to impress upon your minds that it is 

 still a most green and fertile field for the 

 chemist. I have tried to arrange a few 

 familiar experiments to illustrate some of 

 the facts touched upon, and it should be 

 borne in mind that I am trying to interest 

 an audience of chemists from widely dif- 

 ferent fields, rather than to present a chron- 

 ological record of recent experimental re- 

 search. 



I can not tell just when chemistry was 

 first scientifically applied to a study of 

 artificial light. Most cardinal discoveries 

 are made by accident and observation. The 

 first artificial light was not made by design 

 nor was the first improvement the result of 

 chemical analysis. It is supposed that the 

 first lamps were made from the skulls of 

 animals, in which oil was burned. Herod- 

 otus, describing events about three centu- 

 ries before Christ, says of the Egyptians: 

 At the times when they gather together at the 

 city of Sais for their sacrifices, on a certain night 

 they all kindle lamps many in number in the open 

 air round about the houses: now the lamps are 

 saucers full of salt and oil mixed and the wick 



'Presidential address delivered at the Boston 

 meeting of the American Chemical Society, De- 

 cember 29, 1909. 



