VI CONTENTS. 



Page. 



XIII. On the Geological Position of the Mastodon giganteum and 



associated Fossil Remains at Bigbone Lick, Kentucky, 

 and other localities in the United States and Canada ; by 

 Chas. Lyell, Esq., V. P. G. S., &c, - - - 320 



XIV. On the Parallelogram of Forces ; by Prof. Alexander C. 



Twining, 324 



XV. Notice of an Ice Mountain in Wallingford, Rutland Coun- 

 ty, Vermont ; by S. Pearl Lathrop, M. D., - - 331 

 XVI. Views concerning Igneous Action, chiefly as deduced from 

 the Phenomena presented by some of the Minerals and 

 Rocks of the State of New York ; by Prof. Lewis C. 



Beck, M. D., 333 



XVII. On the possible Variation in the Length of the Day, or of 

 the Times of Rotation of the Earth upon its Axis ; by 



Prof. W. W. Mather, 344 



XVIII. An Account of some new Instruments and Processes for 

 the Analysis of the Carbonates ; by Profs. William B. 

 Rogers and Robert E. Rogers, .... 346 

 XIX. Description and Analysis of Pickeringite, a native Mag- 



nesian Alum ; by Augustus A. Hayes, ... 360 

 XX. System of Mineralogy, including the most Recent Dis- 

 coveries, Foreign and American ; by James D. D^na, 362 

 XXI. Abstract of the Proceedings of the Thirteenth Meeting of 



the British Association for the Advancement of Science, 388 



Miscellanies. — Analysis of Meteoric Iron from Otsego County, 

 New York, 401. — Improvements in Cambridge, England, 403. 

 — Association of American Geologists and Naturalists : New 

 Works received, 404. 



Appendix. — Review of and Strictures on Mr. Dana's Reply to Mr. 

 Couthouy's Vindication against his charge of Plagiarism ; by 

 Joseph P. Couthouy, 1. — Reply of J. D. Dana to the fore- 

 going article by Mr. Couthouy, 10. 



