CONTENTS. 



Paoi 



I. A Revision of the Atomic Weight of Barium First Paper: 



The Analysis of Baric Bromide. By Theodore Wii i.i \m 

 Richards 1 



II. On the Development of the Spermogonium of Caoma nitens 



(Schw.). By Herbert Mahle Richard* :;i 



III. On a Thermo-electric Method of studying < 'ylinder Condi n- 



sation in Steam-engines. By Edwin H. Ham 37 



IV. Note on an Approximate Trigonometric Expression for 



Fluctuations of Steam Temperature in on Engir I 



By Edwin H. Hall .".1 



V. Studies on the Transformations of Moths of the Family Satur- 

 niidat. By A. S. Packard, M. D 



i.i 



VI. An Investigation of the Excursion of the Diaphragm of a '/'. 



phone Receiver. By Charles R. Cross \nd ARTHUR 

 N. Mansfielii 



VII. Additions to the Phanogamic Flora of Mexico, red 

 by C. G. Pringle in 1S91-9L'. By B. L. ROBINSON UCD 

 II. E. Seaton 



VIII. New and little known Plant* collected on Mt the 



Summer o/1891. By Henry E. Si \i.i\ . . llfl 



IX. The North American Sileneoz and Polycarpeee. Bt B. I 

 Robinson 



50 



