IV CONTENTS OF VOL. XXI. 



Page 



NUMBER CXXXVL— AUGUST. 



M. Hess on the Scientific Labours of Jeremias Benjamin Richter. 

 Addressed to the Imperial Academy of Sciences of St. Peters- 

 burg, at the public sitting of Dec. 29, 1840 81 



Mr. J. R.Christie on the Extension of Budan's Criterion for 

 the Imaginary Roots, and a new Method of effecting the Se- 

 paration of the nearly equal Roots of a numerical Equation 96 

 The Rev. Prof. Challis on the Analytical Condition of the Rec- 

 tilinear Motion of Fluids 101 



Mr. Gulliver's Contributions to the Minute Anatomy of Ani- 



.mals. No. II 107 



Mr. Baily's Account of some Experiments with the Torsion-rod, 



for determining the Mean Density of the Earth Ill 



Prof. Powell's Note on Mr. Earnshaw's Paper in Phil. Mag. for 



April 1842 122 



The Rev. P. Kelland's Reply to some Objections against the 



Theory of Molecular Action according to Newton's Law . . 124 

 Mr. C. Hood on some peculiar Changes in the Internal Struc- 

 ture of Iron, independent of, and subsequent to, the several 



Processes of its Manufacture » . . 130 



The Rev. Humphrey Lloyd's Notice of a remarkable Magnetic 

 Disturbance which occurred on the 2nd and 4th of July, 1842 137 



Proceedings of the Geological Society 141 



American Philosophical Society 150 



Fourth Meeting of the Italian Congress of Men of Science. ... 153 

 On the Earthquake felt in parts of Cornwall, on February 17, 



1842 153 



On the Blue Colour of Ultramarine, by M. Eisner 156 



Preparation of Oxichloric Acid, by M. Ad. Nativelle 157 



On the Action of Water on Lead, by Prof. Christison 158 



Apothecaries' Hall : appointment of Mr. Warington 159 



Meteorological Observations for June 1842 159 



Table 160 



NUMBER CXXXVIL— SEPTEMBER. 



Mr. W. Francis's Chemical Examination of the Fruit of Meni- 



spermum Cocculus (Semina Cocculi Indici) 161 



Mr. Gulliver's Contributions to the Minute Anatomy of Ani- 

 mals. No. Ill 168 



Mr. F. C. Calvert on the Preparation of Quina and Cinchonia 171 



Prof. J. Booth on a Theorem in Analytic Geometry 176 



Mr. Darwin's Notes on the Effects produced by the Ancient 

 Glaciers of Caernarvonshire, and on the Boulders transported 



by Floating Ice 180 



Mr. J. Rees's Application t i particular instances of the general 

 Formula for eliminating the Weights of Mixed Bases 188 



