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CONTENTS OF VOLUME XX. 



NUMBER I. 



Page. 

 Art. I. On the means of safety in Steam Boats ; by John L. Sul- 

 livan, Civil Engineer, - - - - - 1 

 II. Specification of an improvement in steam engine boilers, 

 for the employment of carburetted hydrogen gas, as 

 fuel ; by John L. Sullivan, Civil Engineer, - - 10 



III. A description of an Economical Steam Boat, - - 14 



IV. Remarks on the prevailing Storms of the Atlantic coast, 



of the North American States; by William C. Redfield, 17 

 V. Observations on a new variety of Peruvian Bark ; with 



some remarks on the alkaline bases Quinia and Cincho- 



nia ; by George W. Carpenter, - - - - 62 

 VI. Analysis of the Protogaea of Leibnitz; by Prof. E. 



Mitchell, of the University of North Carolina, - 66 

 VII. On Central Forces ; by Prof. Theodore Strong, - 65 



VIII On the Transition Rocks of the Cataraqui ; by Cap. R. 



H. Bonnycastle, R. E. Up. Can., with figures — -see 



the plate, - - 74 



IX. Notice concerning the Garden of Fromont, translated 



from the French ; by Jacob Porter, M. D., - 83 



X. Chemical Works, - - 88 



XL Art de se preserver de Taction de la Flamme ; par M. Le 



Chevalier Aldini. — The art of preserving from the 



action of flame; by the Ch. Aldini. Analysis by Prof. 



J. Griscom, ___---- 96 



XII. Geological Communications. 



1. Crotalus? reliquus, or Arundo? crotaloides, - - 122 



2. The Gold of Mexico in a rock, equivalent to that 



which contains the Gold of the Carolinas ; by Prof. 

 Amos Eaton, ______ 124 



3. Scratches on gray wacke in the Alleghany range ; by 



William A. Thompson, of Sullivan county, N. Y., 124 



XIII. Meteorological Observations, made by Dr. S. P. Hil- 



DRETH, at Marietta, (Ohio) in 1830, - - - 126 



XIV. On a singular instance of Crystallization; by Augustus 



A.Hayes, 128 



XV. On a change of climate, ______ 130 



XVI. Fuel for Steam Boilers.— Editor. - - - - 133 



XVII. On the electro-magnetic properties of metalliferous veins 



in the mines of Cornwall ; by Robert Were Fox, of 

 Falmouth, 136 



XVIII. Galvano-magnetism, - - - - - - a)-'^pij*f 



