SCIENCE 



Friday, December 29, 1911 

 contents 



The American Association for the Advance- 

 ment of Science: — 

 Becent Progress in Spectroscopic Methods: 

 Pbofessoe a. a. Michelson 893 



The American Society of Naturalists: — 

 Heredity and Personality: Peofessor Her- 

 bert S. Jennings 902 



Scientific Notes and News 910 



University and Educational News 915 



Discussion and Correspondence: — 



The Positive Ion in Electrical Discharge 

 through Gases: Professor F. E. Nipher. 

 A New Record of a Chestnut Tree Disease 

 in Mississippi: Caroline Eumbold. Stand- 

 ing's Turtle: John J. Schoonhoven. The 

 Moth of the Cotton Worm: J. E. Watson. 

 Transplantation of Ovaries: Dk. C. C. 

 Guthrie. Moulting and Change of Color 

 of Coat in Mice: Professor T. H. Morgan 917 



Quotations : — 

 The Soyal Society 919 



Scientific Books: — 



Voyage of the "Why Not": General A. 

 W. Geeely. Pullf rich's Stereoscopisches 

 Sehen und Messen: Professor Joseph Jas- 

 TEOW. Geerligs's Sugar Industry: Pro- 

 fessor F. G. WiECHMANN. Cohen's Intro- 

 duction to the Lie Theory of One-parameter 

 Groups: Professor G. A. Miller 92o 



Special Articles: — 



The Artificial Mipening of Persimmons: 

 Professor Francis Ernest Lloyd. Fun- 

 dulus and Fresh Water: Professor Fran- 

 cis B. Sumner 934 



Societies and Academies : — 



■ The Botanical Society of Washington: Dr. 

 W. W. Stookberqee. The Torrey Botan- 

 ical Clui : B. O. Dodge 931 



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

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

 Hudson, N. Y, 



THE AMEEICAN ASSOCIATION FOB THE 

 ADVANCEMENT OF SCIENCE 



BECENT PBOGBESS IN SPECTEOSCOPIC 

 METHODS ' 



An observer who for the first time views 

 the light of the sun through a prism can 

 not fail to express his wonder and delight 

 at the gorgeous display of colors into which 

 the white light is separated — and if the 

 observation is made under the same con- 

 ditions as in the celebrated experiment of 

 Newton, 1666, there is in truth nothing else 

 which he could observe. You will remem- 

 ber that he allowed a beam of sunlight to 

 stream through a round opening in a 

 shutter of his window, falling on a glass 

 prism, which bent the sun rays through 

 different amounts depending on their color, 

 thus spreading out the white round sunlit 

 spot on the opposite wall into a colored 

 band — the spectrum — which he rather 

 arbitrarily divided into seven colors — red, 

 orange, yellow, green, blue, indigo and 

 violet. (If the division were made to-day 

 I doubt if indigo would be included.) 

 There is in fact no definite demarcation 

 between these, and they shade insensibly 

 into each other — and if the solar spectrum 

 were always produced under these condi- 

 tions we should say it was continuous, in- 

 deed if it were not the sun but an argand 

 burner or an incandescent lamp which 

 served as source, it would really be so. 



But even if the source consisted of iso- 

 lated (but sufficiently numerous) separate 

 colors, the fact would be disguised by the 

 overlapping of the successive images. In 

 other words the spectrum is not pure. In 



' Address of the president, Washington meeting, 

 December, 1911. 



