Morgan and Tallmon — Occurrence of Bitumen. 369 



alkaline sulphide by heating with metallic sodium is a matter 

 of conjecture only, but it is probable that less than 1 per cent 

 of the tar is sulphur. 



Tests for nitrogen, by heating with sodium and precipitating 

 the cyanide as Prussian blue, failed to indicate the presence of 

 this element even when 0*3 gram of tar was treated. Under 

 these circumstances the resulting solutions gave very strong 

 tests for sulphur but not a particle of the blue precipitate 

 could be obtained even on long standing. 



In order to ascertain the delicacy of this method of detect- 

 ing nitrogen in substances of a nature similar to those which 

 might be expected to be present in the tar, qualitative experi- 

 ments were made with known amounts of pyridine and quino- 

 line. It was found that 0*01 gram of either substance would 

 give a precipitate in such quantity that when diluted to 100 ccm 

 and thoroughly mixed, l ccm would on settling give a distinct 

 indication. Similar results were obtained by mixing the same 

 amounts of pyridine with the tar and then heating with 

 sodium. Certain natural asphalts known to contain nitrogen 

 were tested by this method and gave positive results. Hence 

 it is concluded that the failure to obtain evidence of nitrogen 

 in the present instance was not due to the method. While 

 heating the pyridine with sodium its odor was very apparent 

 in the room, and since it is the most volatile member of this 

 series of compounds it seems highly probable that if nitrogen 

 were present in the tar to the extent of 0*05 per cent it would 

 have been detected. 



JSTo evidence of phosphorus could be found, after oxidizing 

 with fuming nitric acid and testing with molybdate solution. 



JSone of the properties, either physical or chemical, which 

 have thus far been set forth, indicate any difference between this 

 tar and some pure natural asphalts. 



A combustion of 0*1107 gram of the tar for carbon and 

 hydrogen gave 0*2582 gram carbon dioxide and 0*1058 gram 

 water, indicating 63*6 per cent carbon and 10*6 per cent water. 

 These figures give 25*8 per cent oxygen and other elements, 

 determined by difference. Since nitrogen is absent and sul- 

 phur present only in small amounts, oxygen seems to form 

 about one-quarter of the entire substance. 



These percentages do not agree even remotely with the 

 figures given by asphalts, which show generally less than 5 per 

 cent of oxygen. Incomplete combustion may possibly explain 

 this discrepancy but there was no evidence of this during the 

 progress of the combustion. Although a second determination 

 was greatly desirable, the material for it was not at hand. 



It is interesting to note in this connection, however, that 

 certain bituminous substances have been reported as containing 



Am. Jour. Sci. — Fourth Series, Vol. XVIII, No. 107. — November, 1904 

 25 



