CONTENTS. 



Page 

 I. The Development and Application of a General Equation for Free 

 Energy and Physico-Cheviical Equilibrium. By Gilbert 

 Newton Lewis 1 



II. Short Studies of North American Tryxalinae. By Samuel H. 



SCUDDER 39 



III. A Revision of the Atomic Weight of Cobalt. Third Paper. — 



The Analysis of Cobaltous Chloride and Oxide. By Theo- 

 dore William Richards and Gregory Paul Baxter . 59 



IV. On the Thermal Conductivity of Vulcanite. By B. O. Peirce . 73 



V. Tvo Genera of North American Decticinae. By Samuel H. 



Scudder 81 



VI. Note on the Finite Continuous Groups of the Plane. By F. B. 



Williams 95 



VII. The Echelon Spectroscope. By A. A. Michelson 109 



VIII. The Electrochemical Equivalents of Copper and Silver. By 

 Theodore W. Richards, Edward Collins, and George 

 W. Heimrod 121 



IX. Preliminary Diagnoses of Neiv Species of Laboidbeniaceae. — /. 



By Roland Thaxter 151 



X. Ferrous Iodide. By C Loring Jackson and I. H. Derby . 211 



XI. Note on the Constitution of Diparabrombenzylcyanamide. By C. 



Loring Jackson and R. W. Fuller 229 



