IV CONTENTS. 



Num'ber 260. 



Page. 



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

 uids and their Chemical Constitution ; by C. E. Line- 

 - barger — 83 



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

 XIII. — New occurrence of Ptilolite ; by W. Cross and L. 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 



XV. — 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. Gruener. 117 



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



With Cry stallographic 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 



XXI. — Csesium and Rubidium Chloraurates and Bromau- 



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



their Crystallography ; by S. L. Penfield 157 



XXII. — Preliminary Note of a New Meteorite from Kenton 



County, 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, ltO. 



