Vlll CONTENTS. 



NumlDer 96. 



Page 

 Art. XL. — Polar Climate in Time the Major Factor in the 



Evolution of Plants and Animals ; by G. R. Wieland. 401 



XLI. — Note on the Composition of Bredig's Silver Hydro- 

 sols ; by J. C. Blake 43 1 



XLIL — Behavior of Red Colloidal Gold Solutions toward the 



Electric Current and toward Electrolytes ; by J. C. Blake. 488 



XLIII. — Is the Peak of Fernando de Noronha a volcanic plug 



like that of Mont Pele ; by J. C. Branner _..._. 442 



XLIY. — Studies in the Cyperace?e, XX ; by T. Holm 445 



XLV. — Action of Ultra - Violet Light upon Rare' Earth 



Oxides ; by C. Baskerville .. 465 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — New Method for the Determination of the Faintest 

 Traces of Arsenic, A. Gautier : Influence of Small Quantities of Water in 

 bringing about Chemical Reactions between Salts, Perman, 467. — Deter- 

 mination of Argon in the Atmosphere, Moissan, 468. — New Method for 

 Detecting Chlorides, Bromides and Iodides, Benedict and Snell : Quartz 

 Glass, H. Heraeus, 469. — Absorption of Ultra- Violet Rays by Ozone, E. 

 Meyer : Induced Thorium Activity, F. v. Lerch, 470. — Effect of Pressure 

 on Arc Spectra, J. E. Petavel and R. S. H-utton, 471. 



Geology and Mineralogy — United States Geological Survey, 471. — Nebraska 

 Geological Survey : Geological Structure of Monzoni and Fassa, M. M. 

 O. Gordon : North American Plesiosaurs, S. W. Williston, 473. — Spodu- 

 mene from Pala, California, W. T. Schaller, 474. 



Miscellaneous Scientific InteUigence — National Academy of Sciences : Ameri- 

 can Association : Annual Report of the Board of Regents of the Smith- 

 sonian Institution, showing the operations, expenditures and conditions of 

 the Institution for the year ending June 30, 1902: Physico-Chemical 

 Review, M. Rudolpht, 475. 



06i7iiar.j/— Robert Henry Thurston : Henry Carrington Bolton, 475. 

 Index to Vol. XVI, 476. 



