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THE POPULAR SCIENCE MONTHLY 



In this connection I would say that in a paper read before the New 

 York Section of the Society of Chemical Industry in November, 1897, 

 and published in the Journal of the Society for January, 1898, I stated 

 that, in my opinion as the results of investigations extending over 

 eleven years : 



Asphalt is in process of formation to-day. It plainly does not originate as 

 such but is a secondary product resulting from the transformation of suitable 

 lighter forms of bitumen, malthas or even thinner oils into harder bitumen by 

 condensation and polymerization. A reaction in which sulphur, and probably 

 sulphates seem to take an important part. 



This conclusion was based on the fact that an ultimate analysis of 

 the pure bitumen from fourteen solid asphalts from various parts of 

 the world, showed the presence of from 9.76 to 4.78 per cent, of sulphur, 

 while in the softer forms of bitumen which rapidly harden on exposure 

 to the atmosphere, or on heating, notable amounts of sulphur, 2.0 per 

 cent, or over are found. 



The same conclusion seems to have been arrived at, independently 

 and apparently without a knowledge of my investigations, by Dr. D. 

 Holde, of the Royal Testing Laboratory near Berlin. In his book on 

 mineral oils and fats he says: 



A bitumen would be called native asphalt when it contains considerable 

 amounts (2-10 per cent., usually over 4 per cent.) of sulphur not removable by 



Photo, W. H. Rau, Philadelphia. 

 Pier at Goanaco. 



