IV CONTENTS OP VOL. VIII. — FOURTH SERIES. 



I'age 

 Messrs. J. Spiller and W. Crookes* Further researches on the 



Methods of Preserving the Sensitiveness of Collodion Plates. Ill 



Prof. Gerling's Description of two Letter-scales. (With a Plate.) 113 



Dr. Hargreave on the Law of Prime Numbers 114 



M. A. Strecker on the Constitution of Quinine 123 



Sir W. H. Hamilton on some Extensions of Quaternions (con- 

 tinued) 125 



Dr. Day's Mineralogical Notices 137 



Proceedings of the Royal Society 139 



Ontheoccurrence of Zinc in theVegetable Organism, by A. Braun. 156 



On the Composition of Tannic Acid, by A. Strecker 157 



Meteorological Observations for June 1854 159 



Table 160 



NUMBER LL— SEPTEMBER. 



Dr. Schunck on the Action of the Ferment of Madder on Sugar. 161 

 Prof. Boole's Further Observations relating to the Theory of Pro- 

 babilities in reply to Mr. Wilbraham 175 



Prof. Magnus on Red and Black Sulphur 177 



Mr. J. J. Sylvester on some new Theorems in Arithmetic . . 187 

 M. W. Beetz on the power of conducting Electricity assumed 



by Insulators at high Temperatures 191 



Mr. J. F. Brown on a General Method of Substituting Iodine 

 for Hydrogen in Organic Compounds, and on the Properties 



of lodopyromeconic Acid 201 



Mr. C. G. Williams on the presence of Pyridine among the 

 volatile Bases in the Naphtha from the Bituminous Shale of 

 Dorsetshire, and on the fractional Crystallization of Platinum - 



salts 209 



Dr. Woods on Sensitive Collodion 213 



Proceedings of the Royal Society 213 



Cambridge Philosophical Society 234 



On the Artificial Production of Taurine, by A. Strecker 236 



On the Electro -chemical Decomposition of Water, by F. Leblanc. 237 

 On some Combinations of Hydrargyromethyle and Hydrargyr- 



aethyle, by A. Strecker 238 



On the Artificial Production of Cinnamon Oil, by A. Strecker. 238 



Meteorological Observations for July 1854 239 



Table . 240 



NUMBER LIL— OCTOBER. 



M. G. Wertheim on the double Refraction temporarily pro- 

 duced in Isotropic Bodies. (With a Plate.) 241 



