CONTENTS TO VOLUME XXXVII. 



Number 217. 



Page 



Art. I. — Determination of Mineral and Rock Densities at 

 High Temperatures ; by A. L. Day, R. B. Sosman, and 



J. C. HOSTETTER 1 



II. — Notes on a new occurrence of Pisanite and Arsenopyrite, 

 and some large Staurolite Crystals from the Ducktown 

 District, Tennessee ; by F. R. Van Horn 40 



III. — Diagrammatic Representation of Volcanic Phenomena; 



by F. A. Perret. (With Plates I to IV) 48 



IV. — Nipa-palm in the North American Eocene ; by E. W. 



Berry 57 



V. — Modification of the Usual Method of Correcting Silica 



for Included Salts ; by S. B. Kuzirian 61 



VI.— Electrometry with the Displacement Interferometer; 



by C. Barus 65 



VII. — Upper Devonian Delta of the Appalachian Geosyn- 



cline ; by J. Barrell „ . . 87 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Behavior of the Radio-Elements in Precipitation 

 Reactions, Fa jans and Beer : New Source of Gallium, Bardel and 

 Botjlanger, 110. — Ammonium Peroxides, D'Ans and Wedig : Poison of 

 Toads, Wieland and Weil: Quantitative Analysis in Practice, 111. — 

 Constitution of Matter: Mechanics of Particles and Rigid Bodies, 112. — 

 Elementary Treatise on Calculus, 113. 



Geology and Natural History — Conemaugh formation in Ohio, 114. — Cara- 

 docian Cystidea from Girvan : A Contribution to the Paleontology of 

 Trinidad, 115. — Formation of Coal Beds : Contributions to the Geology of 

 the Nordingra Region, 116. — West Virginia Geological Survey, County 

 Reports, 1918. — Iowa Geological Survey : Permo-Carboniferous Verte- 

 brates from New Mexico, 117. — The Meaning of Evolution, 119. — First 

 Principles of Evolution, 120. — Geology and Ore Deposits of the San Fran- 

 cisco and Adjacent Districts, Utah : Nickel Industry, with Special Refer- 

 ence to the Sudbury Region, Ontario, 121. — Curious Lore of Precious 

 Stones : Botanical Features of the Algerian Sahara : Wissenschaftliche 

 Ergebnisse der Deutschen Zentral-Afrika-Expedition 1907-1908 : Labora- 

 tory Manual and Notebook in Botany, 122. — Introduction to the Chemis- 

 try of Plant Products : Modern Problems of Biology : A Laboratory 

 Manual of Invertebrate Zoology : Heredity and Memory, 123. —Bibli- 

 ography of the Tunicata, 1469-1910 : British Parasitic Copepoda ; Cope- 

 poda Parasitic on Fishes : Weathering of Aboriginal Stone Artifacts, No. 1, 

 124. 



Obituary — A. Fritsch : H. Potonie, 124. 



