CONTENTS. 



Page 



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

 The Analysis of Baric Bromide. By Theodore William 

 Richards 1 



II. On the Development of the Spermogonium of Cceoma nitens 



(Schw.). By Herbert Maxtle Richards 31 



III. On a Thermo-electric Method of studying Cylinder Conden- 



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



IV. Note on an Approximate Trigonometric Expression for the 



Fluctuations of Steam Temperature in an Engine Cylinder. 



By Edwin H. Hall 51 



\ 



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



niidcB. By A, S. Packard, M. D 55 



VI. An Investigation of the Excursion of the Diaphragm of a Tele- 

 phone Receiver. By Charles R. Cross and Arthur 

 N. Mansfield 93 



VII. Additions to the Phcenogamic Flora of Mexico, discovered 

 by C. G. Pringle in 1891-92. By B. L. Robinson and 

 H. E. Seaton 103 



Vin. New and little known Plants collected on Mt. Orizaba in the 



Summer of \S^\. By Henry E. Seaton 116 



IX. The North American Silenece and Polycarpece. By B. L. 



Robinson 124 



