CONTENTS. 



Page. 



Art. I. — Studies of the phenomena of Simultaneous Con- 

 trast-Color; and on a Photometer for measuring the 

 intensities of Lights of different Colors ; by A. M. 

 Mater 1 



II. — Kehoeite, a new Phosphate from Galena, Lawrence Co., 



S. D.; by W. P. Headdex... 22 



III. — Ammonium-Lead Halicles; by H. L. Wells and W. 



R. Johnston 25 



IV. — Rubidium-Lead Halides, and a Summary of the Double 



Halides of Lead; by H. L. Wells 34 



V.— The Galveston Deep Well; by E. T. Dumble and G. 



D. Harris . 38 



VI. — Iodometric Determination of the Nitrates; by H. 



Gruener .__ _. _ 42 



VII. — Piedmontite and Seheelite from the Ancient Rhyolite 



of South Mountain, Pennsylvania; by G. H. Williams 50 



VIII. — Cambrian and the Ozark Series ; by G. C. Broad- 

 head 57 



IX.— One-Volt Standard Cell; by H. S. Carhart .. 60 



X. — Cross Roads Meteorite ; by E. E. Howell ._ 67 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Study of Chemical Reactions by means of the Refractive 

 Index, Feet : Preparation of Chlorine by means of Nitric Acid and Manganese 

 dioxide, Lunge and Pret, 68.— Complex Acids containing- Septivalent Iodine, 

 Blomstrand: Refractive Indices of liquid Oxygen, Nitrogen Monoxide and 

 Ethylene, and on the Spectrum of liquid Oxygen, Liveing und Dewar, 69. — 

 Production of Hydrogen Peroxide in the Electrolysis of Sulphuric acid, Kuri- 

 loff: Preparation of Pure Phosphoric oxide, Shenstone and Beck, 70. — Con- 

 stitution of Hydroxylamine, Kolotoff, 71. — Chromophotograph, M. Marey : 

 Reflection of Electrical Waves at the extremity of a linear Conductor, Birke- 

 land: Electrical waves and light waves, V. Bjerknes : New Electrometers, 

 Bjerknes, 72. — Magnetic Properties of liquid Oxygen: Specific Heat of Liquid 

 Ammonia, 7 3. — Value of the meter in English inches, C. B. Comstock : Labora- 

 tory Course in Physical Measurements, W. C. Sabine, 74. 



Geology and Mineralogy — Tertiary Revolution in the Topography of the Pacific 

 Coast, J. S. Diller, 74. — Urnatella gracilis, C. B. Davenport: Lehrbuch der 

 geologischen Formations-Kunde, Kayser: Mineral Resources of the U. S., 75. 

 — Mineralogie de la France, A. Lacroix: Sodalite-syenite from Montana, Lind- 

 GREN and Melville: Summary of Progress in Mineralogy and Petrography 

 in 1892. W. S. Baylet: Australian Meteorite, 76. 



Botany — Plants of Orizaba: Pie natiirlichen Pflanzenfamilien, 76. — Rainfall and 

 Leaf -form: Turgescence and transpiration in fleshy plants, E. Aubert: Origin 

 of Endogens from Exogens, G-. Henslow, 77. 



Miscellaneous Scientific Intelligence — American Association for the Advance- 

 ment of Science, 78. — Australasian Association for the Advancement of Sci- 

 ence: British Association: Owen Memorial: Die Fortentwicklung der elec- 

 trischen Eisenbahn-Rinrichtungen, L. Kohlfurst, 79. — Gravity Research. 

 Determinations of Gravity with half-second Pendulums, T. C. Mendenhall: 

 Colors of Cloudy Condensation, C. Barls: Outlines of Forestry, Houston: 

 Naples Zoological Station : Krantz's Catalogue of Rocks: Manual of Machine 

 Drawing, Low and Bevis: Hawks and Owls of the U. S., Fisher. 80. 



