CONTENTS. 



Page 



Art. XXVIII. — Ultimate Disintegration Products of the 



Radio-active Elements ; by B. B. Boltwood 253 



XXIX. — Use of the Rotating Cathode for the Estimation 



of Cadmium taken as the Sulphate ; by C. P. Flora .. 268 



XXX. — Crystallization of Luzonite ; and other Crystallo- 



graphic Studies ; by A. J. Moses 277 



XXXI. — Determining of the Optical Character of Birefract- 



ing Minerals ; by F. E. Wright 285 



XXXII. — Groups of Efficient Nuclei in Dust-Free Air ; by 



C. Barus 297 



XXXIII. — Studies in the Cyperacese ; by T. Holm___ 301 



XXXIV. — Preliminary Note on some Overthrust Faults in 



Central New York ; by P. F. Schneider 308 



XXXV. — Petrography of the Tucson Mountains, Pima Co., 



Arizona ; by F. N. Guild 313 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Gases produced by Actinium, Debierne : New 

 Heavy Solution, Duboin, 319. —Hydrolysis of very Concentrated Ferric 

 Sulphate Solutions, Recoura : Separation of Gold from the Metals of the 

 Platinum Group, Jannasch and von Moyer : Determination of Sugar with 

 Fehling's Solution, Lavalle, 320.— Slow Transformation Products of 

 Radium, E. Rutherford, 321. 



Geology and Mineralogy — Indiana, Department of Geology and Natural 

 Resources, Twenty-ninth Annual Report, W. S. Blatchley, 322.— Geo- 

 logical Survey of Louisiana : Geological Survey of New Jersey : Brief 

 descriptions of some recently described Minerals, 323. 



TEW-VOLUME IXDEX. 



An extra number, containing a full Index to volumes XI to XX of the 

 Fourth Series, will be ready in December. Sent only to those who specially 

 order it. Price one dollar. 



