11 CONTENTS. 



PAGE 



Art. VII. On the Structure of the Lunar Surface, and its rela- 

 tion to that of the Earth. By James Nasmyth, 

 Esq 267 



VIII. On the Probable Relation between Magnetism and the 

 Circulation of the Atmosphere, especially the 

 Trade Winds. By M. F. Maury, Lieut. United 

 States Navy. Communicated to the Hon. W. A. 

 Graham, Secretary of the Navy, . . 271 



IX. On the late Periodical Visitation of the Aurora 

 Borealis in North America. By Professor D. 

 Olmsted, 293 



X. On a New Test for Iodides. By David S. Price, 



Ph. D., F.C.S., 298 



XI. Parallel between the Superficial Deposits of the Basin 

 of Switzerland and those of the Valley of the Po 

 in Piedmont. By Dr Charles Martins and B. 

 Gastaldi, ...... 300 



XII. On Ventilation by the Parlour Fire. By William 

 HosKiNG, Esq., Professor of Architecture and of 

 Engineering Constructions at King's College, 

 London, ' 302 



XIII. On the Composition of the Waters of the Dee and 



Don, at Aberdeen. By John Smith, M.D., For- 

 dyce Lecturer on Agriculture in Marischal Col- 

 lege, Aberdeen, . . . . . 309 



I. General Character of the districts drained by the 



Rivers Dee and Don, . . . . 309 



II. Composition of Dee Water, . . . 311 



III. Action of Clark's Soap-Test on Dee Water, . 313 



IV. Composition of Don Water, . . . 314 



XIV. An Inquiry into the Cause which renders the Water 



of the Dead Sea unfitted for the support of Animal 



