CONTENTS OF VOL. IV. 



(FOURTH SERIES.) 



NUMBER XXII.— JULY 1852. 



Page 



Prof. Powell's Remarks on Lord Brougham's "Experiments 

 and Observations on the Properties of Light," &c. inserted 



in the Phil. Trans. 1850, Part 1 1 



Prof. Thomson on the Dynamical Theory of Heat, with nume- 

 rical results deducedfromMr. Joule's equivalent of a Thermal 



unit, and M. Regnault's Observations on Steam 8 



Mr. W. Crovvder on the Fatty Acid of Cocculus indicus 21 



Mr. T. T. Wilkinson's Additions to the late Mr. T. S. Davies's 

 Notes on Geometry and Geometers. The Swale Manu- 

 scripts 28 



Mr. M. Donovan on the supposed Identity of the Agent con- 

 cerned in the Phsenomena of ordinary Electricity, Voltaic 

 Electricity, Electro -magnetism. Magneto -electricity, and 



Thermo-electricity (cow/i/H^ec/) «^3 



Mr. T. H. Henry on the Composition of Wootz, or Indian Steel. 42 



Mr. J. Napier on Copper Smelting 45 



Captain Lefroy's Second Report on Observations of the Aurora 



Borealis, 1850-51, made by the Non-commissioned Officers 



of the Royal Artillery, at the various Guard-rooms in Canada. 59 



Notices respecting New Books: — Captain W. H. Smyth on 



^des Hartwellian?e, or Notices of the Manor and Mansion of 



Hartwell 69 



On the Composition of Human Fat, by Dr. Heintz 75 



New arrangement of the Voltaic Pile, by M. Fabre de Lagrange. 77 

 On the preparation of Pure Silver from Chloride of Silver, 



by C. 13runner 78 



The Bomerang, by J. E. Gray. F.R.S 79 



Meteorological Observations for May 1852 79 



Meteorological Observations made by Mr. Thompson at the 

 Garden of the Horticultural Society at Chiswick, near 

 London; by Mr. Veall at Boston; and by the Rev. C. 

 Clouston at Sandwick Manse, Orkney 80 



NUMBER XXIIL— AUGUST. 



Dr. Barry's Renewed Inquiries concerning the Spiral Structure 

 of Muscle, with 0])8ervations on tlie Muscularity of Cilia. 

 (With Two Plates.) 81 



