CONTENTS. 



Page 



Art. XL — Relations between the Surface Tensions of Liq- 

 uids and theii' Chemical Constitution; by C. E. Line- 

 barger .. . - - 83 



XII— Gold Deposit at Pine Hill, Gal.; by W. Lindgren... 92 



XIII. — New occurrence of Ptilolite; by W. Cross andL. G. 



Eakins .. ;..' . . -■ 96 



Appendix. — Note on the Constitution of Ptilolite and Mor- 



denite; by F. W. Clarke 101 



XIV.— Separation of Magnesium Chloride from the Chlorides 

 of Sodium and Potassium by means of Amyl Alcohol ; 

 by R. B. Riggs 103 



XY. — Great Shear-zone near Avalanche Lake in the Adiron- 



dacks ; by J. F. Kemp ■_ 109 



XVI. — Herderite from Hebron, Maine; by H. L. Wells 



and S. L. Penfield .. . . 114 



XVII. — Method for the Iodometric Determination of Ni- 

 trates; by F. A. Gooch and H. W. Grit enter . . 117 



XVIII. — Some Alkaline Iodates; by H. L. "Wheeler. 



With Crystallographic Notes ; by S. L. Penfield 123 



XIX. — Development of the Brachiopoda. Part II; by C. 



E. Beecher. (With Plate I) ._ '. 133 



XX. — Some Double Halides of Silver and the Alkali-metals ; 

 by H. L. Wells and H. L. Wheeler. With their 

 Crystallography; by S. L. Penfield 155 



XXL— Caesium and Rubidium Chloraurates and Bromau- 

 • rates; by H. L. Wells and H. L. Wheeler. With 

 their Crystallography ; byS.L. Penfield 157 



XXII. — Preliminary Note of a New Meteorite from Kenton 



Couuty, Kentucky ; by H. L. Preston 163 



XXIII. — Additional observations on the Jura-Trias trap of 



the New Haven Region ; by J. D. Dana 165 



XXIV. — Notes on Mesozoic Vertebrate Fossils; by O. C. 



Marsh. (With Plates II-V.) 171 



SCIENTIFIC INTELLIGENCE. 



Miscellaneous Scientific Intelligence — Natural Science : A monthly review of Scien- 

 tific Progress: Catalogue of Scientific Papers (1874-1883): Experiments with 

 alternate currents of high potential and high frequency, by Nikola Tesla, 170. 



