IV CONTENTS. 



Number 272. 



Art. XI. — Use of Cnpric Nitrate in the Voltameter, and 



the Electro-Chemical Equivalent of Copper; by F. E. 



Beach _ __ 81 



XII. — Double Halides of Arsenic with Caesium and Rubidium; 



and on some Compounds of Arsenious Oxides with the 



Halides of Caesium, Rubidium and Potassium; by H. L. 



Wheeler 88 



XIII. — Mackintoshite, a new Thorium and Uranium Mineral ; 



by W. E. Hidden : with analyses by W. F. Hillebrand 98 

 XIV. — Alnoite containing an uncommon Variety of Melilite ; 



by C. H. Smyth, Jr. . _ 104 



XV. — Canfieldite a new Germanium Mineral and on the 



Chemical Composition of Argyrodite; by S. L. Penfield 107 

 XVI. — Epeirogenic Movements associated with Glaciation ; 



by W. Upham 114 



XVII. — Antennae and other Appendages of Triarthrus Beckii; 



by W. D. Matthew. (With Plate I.) 121 



XVIII. — Reduction of Nitric Acid by Ferrous Salts; by 



C. F. Roberts 126 



XIX. — Concerning the Structure of Caoutchouc ; by H. F. 



Lueders _. 135 



XX. — Fisher's New Hypothesis; by G. F. Becker 137 



XXI. — Criticism of Mr. Fisher's Remarks on Rock Fusion; 



by C. Barus 140 



XXII. — Larval forms of Trilobites from the Lower Helder- 



berg Group; by C. E. Beecher. (With Plate II.) 142 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— F\ame Spectra at High Temperatures. Parti. Oxy- 

 hydrogen Blowpipe Spectra, W. N. Hartley. 148. — New Calcium Lines, J. M. 

 Eder and E. Valenta: Hall Effect in Iron, Cobalt and Nickel, Kundt: Meas- 

 urement of Electrical Resistance by means of alternating Currents, P. Kohl- 

 rausoh: New Form of Induction Balance, Wien, 150. — Specific Resistance of 

 Mercury, J. V. Jonfs: Photography of the Hertz Spark, Emden: Green's use of 

 "potential," G. F. Becker. 151. — Physical Review, E. L. Nichols and E. Mer- 

 ritt: Polarization Rotatoire. Reflexion et Refraction vitreuses; Reflexion 

 Metallique, G. Foussereau, 152. 



Geology and Natural History— Lehrbuch der Petrographie, F. Zirkel, 152. — 

 Ueber das Nonan oder Ober-Laurentian von Canada, F. D. Adams, 153. — Brief 

 notices of some recently described Minerals: Zoisite from the Flat Rock Mine, 

 Mitchell Co., N. C, W. E. Hidden: Optical examination of Cacoxenite, L. M. 

 Luquer, 154 — Great Barrier Reef of Australia, W. S. Kent, 155. — Amount of 

 water in the soil after a period of severe drought, M. Reiset, 1 57. — Nitrification, 

 M. Deh^rain: Action of the Pyocyanic bacillus on plants, M. Charrin, 158. 



Miscellaneous Scientific Intelligence — John Strong Newberry Fund: Cordoba 

 Durchmusterung. Brightness and position of every fixed star down to the 

 tenth magnitude comprised in the belt of the heavens between 22 and 32 de- 

 grees of south declination, J. M. Thome, 159. — Smithsonian Meteorological 

 Tables : Forest Influences : Ostwald's Klassiker der exakten Wissenschaften 

 Leipzig: Celestial Mechanics: Blaisdell's Physiologies, 160. 



