Trans. N. V. Ac. Sci. 50 Dec. ii, 



tarry. These differ widely also in chemical composition : some 

 yielding much asphalt by distillation, resembling a solution of asphalt 

 in]_turpentine ; some containing so much paraffine, that a considera- 

 ble quantity can be strained out in cold weather. The asphalt in 

 its natural form is a solid rock, to which the term " gum beds" has 

 been applied in Canada. These differences in constitution have 

 originated in'the differences in the bituminous shales from which the 

 petroleum, ozokerite, etc., have been derived. In Canada, as exca- 

 vations are sunk through the asphalt, this becomes softer and softer, 

 and finally passes into petroleum. This is also the case in Utah. 

 Mr. Lay has become interested in the material, has visited all the 

 localities of its occurrence, and is best acquainted with them. 

 A paper was then read by Dr. John S. Newberry, on 



THE PHYSICAL CONDITIONS UNDER WHICH COAL WAS FORIMED. 



[Published in School of Mines Quarterly, 1883]. 



Discussion. 



Dr. B. N. Mari'IN enquired whether any graduation has been re- 

 cognized in the types of plants, in passing through the Coal-meas- 

 ures from below upwards. 



Dr. Newberry replied that differences existed, but the types were 

 largely interlocked by insensible changes. Some floras prevail 

 throughout the series : while, on the other hand, other types, e.g., the 

 sigillaria, are abundant below, but in passing upward, decrease and 

 and disappear. 



December 11, 1882. 

 Section of Chemistry. 



The President, Dr. J. S. Newberry, in the Chair. 

 Fifty-six persons present. 



A crystallized specimen of native gold, of remarkable beauty, 

 from El Dorado, Cal., belonging to Mr. Terry, was exhibited by 



