VI CONTENTS. 



ARTICLE PAGE 



IX. — On the Origin of Elementary Substances, and on some new 

 Eelations of their Atomic Weights. By Henry Wilde, 

 Esq ii8 



X. — On the Velocity with which Air rushes into a Vacuum, and on 

 some Phenomena attending the Discharge of Atmospheres 

 of Higher into Atmospheres of Lower Density. By Henry 

 Wilde, Esq. (and Table.) 146 



XI. — On the Flow of Gases. By Professor Osborne Reynolds, 



LL.D., F.R.S 164 



XII. — On the EiHux of Air as modified by the Form of the Dischar- 

 ging Orifice. By Henry Wilde, Esq 182 



XIII. — On the Morphology of Finites oblo7igus {Abies ohlonga of 

 Lindley and Hutton). By Wm. Ckawpord Williamson, 

 LL.D., F.R.S., Professor of Botany in Owens College. 

 (Plate IX.) 189 



XIV. — On the Hymenoptera of the Hawaiian Islands. By the Rev. 



T. Blackburn, B.A., and P. Cameron 194 



XV. — The Pollution of the River Irwell and its Tributaries. By 



Charles A. BuRGiiARDT, Ph.D. (Plates X.-XIII. & Table.) 245 



XVI. — On the Eelations of Calamodendron to Calamites. By Pro- 

 fessor W. C. Williamson, LL.D., F.R.S. (Plates XIV.- 

 XVI.) 25s 



