co:ntf"~ t olume xll 



Nuil. -41. 



Art. I. — A Geologic Reconnaissance of the Cuzco Valley, 



Peru ; by H. E. Gregory (With Plates I and II) .'... 1 



II. — An Achromatoscope ; by S. R. Williams - 101 



III. — The Life of Radium; by Ellen Gleditsch — 112 



IV. — Some New Mineral Occurrences from the Tintic Dis- 

 trict, Utah; by A. H. Means . 125 



V. — The Present Status of the Investigation of the Origin 



of Barrier Coral Reefs; by T. W. Vaughan 131 



VI. —Relations of Coral Reefs to Crust Movements in the 



Fiji Islands; by E. C. Andrews 135 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Separation of Yttrium from the Yttrium Earths, 

 J. B. Bonardi and C. James: Volumetric Method for Potassium, G. Ajon, 

 142. — Potash from Feldspar, 143. — Introduction to Chemical Analyses, 

 E. W. Rockwood: Laboratory Manual arranged to accompany " A Course 

 in Chemistry," W. McPherson and W. E. Henderson: Fluorescence and 

 Eesonance of Sodium Vapor, R. J. Strtjtt, 144. — /3-Rays from Radium D. 

 L. Meitner, 145. — Introduction to Magnetism and Electricity, E. W. E. 

 Kempson: Introduction to the Mechanics of Fluids, E. H. Barton, 149, 



Geology and Natural History — Triassic Life of the Connecticut Valley, R. S. 

 Lull, 147. — Central Connecticut in the Geologic Past, J. Barrell : 

 Bibliographic Index of American Ordovician and Silurian Fossils, R. S. 

 Bassler, 148. — Fifth Annual Report of the Director of the Bureau of 

 Mines: Determinative Mineralogy, J. V. Lewis. 149. — Monograph of the 

 Existing Crinoids, A. H. Clark : Practical Zoology, R. W. Hegner: 

 Course in Invertebrate Zoology, H. S. Pratt, 150. — Meaning of Evolution, 

 S. C. Schmucker: Lessons in Elementary Physiology, T. H. Huxley: 

 Diversions of a Naturalist, R. Lankester: Beekeeping, E. F. Phillips, 

 151. 



Obituary — A. W. Wright: 0. A. Derby: C. F. Holder: H. E. Roscoe : H. 

 C. Bastian: C. J. Bouchard: R. Assheton: A. Rucker: G. Vasseur, 152. 



Note.— The extra expense involved in the publication of the article on the Cuzco 

 Valley by H.E.Gregory (pp, 1-100), particularly as to illustrations and maps, has 

 been assumed by the National Geographic Society of Washington.— Ed. 



