CONTENTS. 



Page 

 I. Observations of the Mean Right Ascension of Certain Polar 



Stars, made at the Field Memorial Observatory of Williams 



College, and reduced to the Epoch 1SS4-0. By Truman 



Henry Safford 1 



II. Thunder- Storms in New England in the Summer of 1885. By 



William Morris Davis 14 



III. A Preliminary Synopsis of North American Carices, including 



those of Mexico, Central America, and Greenland, with the 

 American Bibliography of the Genus. By L. H. Bailey, Jr. 59 



IV. Contributions from the Chemical Laboratory of Harvard College. 



I. Analysis of Mica from Leon Co., Texas. By George W. 

 Leighton 158 



II. Analysis of a Crystalline Scale formed in the Manufacture 

 of Sodic Bicarbonate by the Ammonia Process at Syracuse, 



N. Y. By George W. Leighton 159 



III. On the Constancy in the Heat produced by the Reaction 

 of Argentic Nitrate on Solutions of Metallic Chlorides. By 

 Theodore W. Richards 162 



IV. Is there a Constant Relation between the Heats of Forma- 

 tion of Chlorides and Sulphates in A queous Solution ? By 

 Irving W. Fay 164 



V. A Method for the Separation and Estimation of Boric Acid, 

 with an Account of a Convenient Form of Apparatus for 

 Quantitative Distillations. By F. A. GoocH 167 



