15 



Observations to determine the Magnetic Dip at Baltimore t 

 Philadelphia, New York, West Point, Providence, Spring- 

 field, and Albany, By A. D. Bache, Professor of Natural 

 Philosophy and Chemistry, and Edward H. Courtenay, Pro- 

 fessor of Mathematics, in the University of Pennsylvania. 

 Presented by the former. 



On the relative horizontal Intensities of terrestrial Mag- 

 netism at several Places in the United States, By the same. 



Analysis of some of the Coals of Pennsylvania. By H. D. 

 Rogers, F. G. S. London, and Professor Bache, &c. Pre- 

 sented by the latter. 



Notes and Diagrams, illustrative of the Directions of the 

 Forces acting at and near the Surface of the Earth, in diffe^ 

 rent Parts of the Brunswick Tornado of June I9th, 1835. 

 By x\. D. Bache, Professor of Natural Philosophy and Che- 

 mistry in the University of Pennsylvania. 



The same author presented also the following papers to 

 the Academy : 



Remarks on a Method, proposed by Doctor Thomson, for 

 determining the Proportions ofPotassa and Soda in a mixture 

 of the two Alkalies. 



Note relating to the hardening of Lime under Water, by 

 the Action of Carbonate of Potassa, &c. 



On the comparative Corrosion of Iron, Copper, Zinc, %c. 

 by a saturated Solution of common Salt. 



Memoir on the Elastic Force of the Vapour of Mercury at 

 different Temperatures. By M. Avogadro. (Translated by 

 Prof. Bache.) 



An Essay on Chemical Nomenclature. By J. J. Berzelius. 

 (Translated from the French, with Notes, by Prof. Bache.) 



Historical Notes. 



Note of the Effect upon the Magnetic Needle of the Aurora 

 Borealis, visible at Philadelphia on the 17 th of May, 1833. 



Diagrams for illustrating a Register of the Direction of 

 the Wind. 



