CONTENTS. 
PAGE 
A relation between the velocity and volume of organic ions in aqueous 
solutions. By G. A. Cause and T. H. Laby. (Communicated by 
Prof. J. J. Thomson) ......... 1 
Note on a Collection of Oribatidae from British Guiana. By C. War- 
burton and N. D. F. Pearce 13 
The Radioactivity of the Alkali Metals. By Norman R. Campbell 
and Alexander Wood .15 
On the Maturation of the Germ-Cells in the Sawfly, Nematus ribesii 
(Third Note). By L. Doncaster . . - 22 
A delicate reaction for Carbohydrates. By H. J. H. Fenton . . 24 
The Solubility of Stereoisomerides in Optically Active Solvents. By 
H. 0. Jones . 27 
The influence of spectral colours on the sporulation of Saccharomyces. 
By J. E. Purvis and G. R. Warwick 30 
The influence of a strong magnetic field on the spark spectra of titanium , 
chromium and manganese. By J. E. Purvis .... 41 
On the Specific Heat of Gases at constant volume and high pressure. 
By W. A. Douglas Rudge 85 
Estimation of Copper. .By W. H. Foster. (Communicated by H. O. 
Jones) . .. . 90 
The procession of Cnethocampa pinivora, Treitschke. By H. EL Brindley 98 
Electrification produced by heating Salts. By Prof. J. J. Thomson . 105 
On Secondary Rontgen Radiation. By Prof. J. J. Thomson . . 109 
A New Chemical Test for “ Strength ” in Wheat Flour. By T. B. Wood 115 
Preliminary Note upon the Presence of Phosphorus in Crystalline Egg 
Albumin. By Miss E. G. Willcock and W. B. Hardy . . 119 
