CONTENTS. 



PAQE 



I. Contributions from the Chemical Laboratory of Harvard College. 



By Josiah Parsons Cooke 1 



II. On the Spectrum of Arsenic. By Oliver W. Huntington 35 



III. Thermoelectricity. — Peltier and Thomson Effects. By 



Charles Bingham Penrose 39 



IV. Thermoelectric Line of Copper and Nickel below 0°. By 



Charles Bingham Penrose 47 



V. Crystalline Form of Cryolite. By W. H. Melville ... 55 

 VI. Researches on the Complex Inorganic Acids. Phospho-molyb- 



dates. By Wolcott Gibbs, M.D . 62 



VII. An Indirect Determination of Chlorine and Bromine by Elec- 

 trolysis. By' Leonard P. Kixnicutt 91 



VIII. Contributions from the Chemical Laboratory of Harvard Col- 

 lege. By Charles F. Mabery 94 



IX. On Certain Substances obtained from Turmeric. — I. Curcumin. "^ 



By C. Loring Jackson and A. E. Menke 110 



X. Contributions from the Chemical Laboratory of Harvard Col- 



lege. By Henry B. Hill 125 



XI. XV. — Simple Method for Calibrating T'hermometers. By 



Silas W. Holman 157 



XII. Contributions to North American Botany. By Asa Gray . 163 



XIII. The Wedge Photometer. By Edward C. Pickering . . 231 



XIV. On the Color and the Pattern of Insects. By Dr. II. A. 



Hagen 234 



