SCIENCE 



A WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISHING THE 



OFFICIAL NOTICES AND PROCEEDINGS OF THE AMERICAN ASSOCIATION 



FOR THE ADVANCEMENT OF SCIENCE. 



Friday, September 21, 1906. 



GOls^TEIlTS. 

 The British Association for the Advancement 

 of Science: — 

 Address before the Section of Mathematics 

 and Physics : Principal E. H. Geiffiths . . 353 



The American Association for the Advance- 

 ment of Science: — 

 Section E — Geology and Geography: Du. 

 Edmund Otis Hovey 365 



Scientific Books: — 



Zsigmondy's ' Zur Erhermtnis der Kolloide : 

 Peofessok S. Lawrence Bigelow 872 



Scientific Journals and Articles 374 



Discussion and Correspondence: — 



When did Franklin invent the Lightning- 

 rod?: A. Lawrence Rotch. Dried Cotton 

 Cultures once more: Dr. George T. Moore. 374 



Special Articles: — 



Geology of South Brazil: Professor I. C. 

 White 377 



The Forest Districts of Uganda 379 



Appointments and Removals at Stanford 

 University 380 



Scientific Notes and News 381 



University and Educational News 384 



MSB. intended for publication and books, etc., intended foi! 

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

 Hudson, N. Y. 



THE BRITISH ASSOCIATION FOR TEE 

 ADVANCEMENT OF SCIENCE. 



ADDRESS BEFORE THE SECTION OF 

 MATHEMATICS AND PHYSICS. 



My predecessors in this chair have in 

 general been able to make communications 

 to the section conveying the results of in- 

 vestigations of their own, or enunciating 

 some principle which would throw a fresh 

 light on the discoveries of others. Mine is 

 a far less happy lot. During the past four 

 years and a half I have been engaged in 

 administrative duties of such a nature that 

 no time has been available for personal 

 scientific work, and little energy even for 

 the study of the work of others. In these 

 circumstances it might Jiave seemed more 

 fitting if I had refused the honor which the 

 council of the British Association conferred 

 upon me by the request that I would under- 

 take the arduous duties which fall to the 

 lot of the president of Section A. Never- 

 theless, after much hesitation, I decided to 

 accept the invitation, in the hope that as a 

 looker-on at the struggle of others, and 

 with the experience of an old participator 

 in the fray, I might be able to commimicate 

 some impressions which had possibly es- 

 caped the notice of those whose attention 

 was necessarily more directed to some spe- 

 cial branch of inquiry. 



I trust that these words of apology may 

 to some extent explain the nature of what 

 must appear a fragmentary discourse. 



In the interval which has elapsed since 

 the last meeting of the association we have 

 lost many men whose names were household 



