CONTENTS OF VOLUME XLIII 



NUMBER I. 



Page. 



Art. I. Geological and Statistical Notice of the Coal Mines in 



the vicinity of Richmond, Va. ; by A. S. Wooldridge, 1 

 II. Regarding Human Foot-Prints in Solid Limestone ; by 



David Dale Owen, M. D., with a plate, ■ - - 14 



III. On the Identity of Pyrochlore with the Microlite of Prof. 



Shepard ; by J. E. Teschemacher, and A. A. Hayes, 33 



IV. On the Wisconsin and Missouri Lead Region ; by 



James T. Hodge, 35 



V. Observations on Photographic Processes ; by William 



F. Channing, 73 



VI. On the Principle of Virtual Velocitfes ; by Prof. Theo- 

 dore Strong, ....... 77 



VII. A dangerous Property of Wood Ashes exposed, and some 

 of their other Properties examined ; by Dr. John T. 



Plummer, 80 



VIII. Caricography ; by Prof. C. Dewey, with a plate, - 90 



IX. On the Dip and Variation of the Magnetic Needle in the 



United States ; by Prof. Elias Loomis, - - - 93 

 X. On the Want of Identity between Microlite and Pyro- 

 chlore ; by Prof. Charles Ufham Shepard, - - 1 16 



XL Additional Objections to Redfield's Theory of Storms ; 



by Prof. Robert Hare, M. D., - - - - 122 



XII. Notice of two New Fossil Mammals from Brunswick 



Canal, Ga. ; with observations on some of the fossil 

 quadrupeds of the United States ; by R. Harlan, M.D., 

 with a plate, ..---.-- 141 



XIII. Description of a New Species of Thracia ; by Prof. C. 



B. Adams, 145 



nu9 r 



