CONTENTS. Vll 



Number 239. 



Page 



Art. XXXII. — Experimental Studies and Observations on 



Ice Structure ; by O. D. von Engeln .- 449 



XXXIII. — A Mounted Specimen of Dimetrodon incisivus 



Cope, in the University of Michigan ; by E. C. Case .. 474 

 XXXIV. — A Fossil Ruminant from Rock Creek, Texas, 



Preptoceras mayfieldi sp. nov. ; by E. L. Troxell 479 



XXXV. — The Separation and Estimation of Aluminium and 



JBervllium by the Use of Acetyl Chloride in Acetone ; 



by il. D. Minnig 482 



XXXVI. — On the Interferences of Crossed Spectra and on 



Trains of Beating Light Waves ; by C. Bartjs 486 



XXXVII— The Brandywine Formation of the Middle 



Atlantic Coastal Plain ; by W. B. Clark 499 



XXXVIII. — On Two Burners for the Demonstration and 



Study of Flame Spectra ; by P. E. Browning 507 



XXXIX. — On the Preparation of Glycocoll and Diethyl Car- 

 bonate ; by W. A. Drttshel and D. R. Knapp 509 



XL. — On the Preparation and Properties of Hydracrylic 



Esters ; by W. A. Drushel and W. H. T. Holden 511 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Volumetric Estimation of Lead, F. D. Miles: 

 Search for an Alkali-Metal of Higher Atomic Weight than Caesium, G. P. 

 Baxter, 514. — Experimental Organic Chemistry, J F. Norris: Labora- 

 tory Experiments in Organic Chemistry, E. P. Cook: Elements of Physical 

 Chemistry, H. C. Jones: Alcoholornetric Tables, E. Thorpe, 515. — Brief 

 Course in Metallurgical Analysis, H. Ziegel: Characteristics of Long 

 Direct-Current Arcs, W. Grotrian, 516. — Prinzipien der Atomdynamik, 

 J. Stark: Ten Years' Work of a Mountain Observatory, G. E. Hale, 517. 

 Electrical Nature of Matter and Radioactivity, H. C. Jones: Book of Wire- 

 less, A. F. Collins, 518. — Plane Geometry, C. I. Palmer and D. P. 

 Taylor, 519. 



Geology and Mineralogy — Publications of the United States Geological Sur- 

 vey, G. O. Smith, 519. — Relation of the Cretaceous Formations to the 

 Rocky Mountains in Colorado and New Mexico, W. T. Lee : Conceptions 

 regarding the American Devonic. J. M. Clarke: Fauna of the San Pablo 

 Group of Middle California, B. L. Clark: Cretaceous Sea in Alberta, D. B. 

 Dowling, 521. — Wabanalron Ore of Newfoundland, A. O. Hates: Yukon- 

 Alaska International Boundary, between Porcupine and Yukon Rivers, D. 

 D. Cairnes: Ordovician Rocks of Lake Timiskaming, M. Y. Williams: 

 Structural Relations of Pre-Cambrian and Palaeozoic Rocks North of the 

 Ottawa and St. Lawrence Valleys, E. M. Kindle and L. D. Burling, 522. — 

 Geology of Franklin County, A. M. Miller: Revision of the Tertiary Mol- 

 lusca of New Zealand, H. Sitter: Third Appendix to the Sixth Edition of 

 Dana's System of Mineralogy, 523. 



Miscellaneous Scientific Intelligence — Publications of the Carnegie Institu- 

 tion of Washington, 523. 



Obituary — J. H. Fabre : T. Boveri : H. G. J. Moselet : D. T. Gwynne- 

 Vaughan: W. Watson: A. J. DuBois, 524. 



