Peckham and Linton — Trinidad Pitch. 203 



14:0 o -150 o F. Outside the lake the deposit is covered with 

 from 2 to 15 feet of earth, rubbish and vegetation. The large 

 area in the center of the lake from which, for convenience, the 

 commercial lake pitch is removed, is bare and black, exposed 

 to the full rays of the tropical sun. Shallow pools of water 

 on the surface of the lake appear to have a temperature of 

 about 100° F. The pitch is probably hotter. It is therefore 

 reasonable to suppose that if evaporation of light oils were 

 taking place that the pitch in the lake would be " driest." Our 

 examination has shown us that both land and lake pitch con- 

 tain oils volatile under the boiling point of water in about the 

 same proportion ; small in both cases. 



The use of both turpentine and chloroform as solvents for 

 asphaltene is based upon observations made a year ago upon 

 the methods employed for the technical analysis of asphaltum. 

 Is was found that in the United States carbon disulphide has 

 been almost exclusively used as a solvent for asphaltene, while 

 in Europe spirits of turpentine has been used for the same pur- 

 pose. Careful experiment showed that neither of these sol- 

 vents would dissolve all of the bitumen from the specimens in 

 our possession, among which were those from the valley of the 

 Rhone. It was observed that turpentine left a large and vary- 

 ing residuum when applied to nearly all of the American 

 specimens, including Trinidad, and that only a very small per- 

 centage was left from the Rhone specimens and those from the 

 Indian Territory. It was also found that in either case chloro- 

 form alone effected a complete extraction of the bitumen. 

 Later we received a specimen of JNeufchatel asphaltic rock 

 from which turpentine completely dissolved the bitumen. 

 This led to an examination and classification of the various 

 bitumens with reference to the action of turpentine. It was 

 found that a large percentage of the asphaltene of Grahamite 

 and a varying percentage of the asphaltene of Trinidad pitch 

 and the asphaltums of California is insoluble in turpentine. It 

 was also found that the asphaltene of the bitumens of Texas 

 and the valley of the Rhone is almost wholly soluble in tur- 

 pentine, and further that when the bitumen is removed from 

 solution from these asphaltic rocks it is not a solid asphaltum 

 but a semi-solid viscous fluid, that does not become solid by 

 exposure, but has remarkable stability in the atmosphere. 

 These facts lead to the belief that the proportion of asphaltum 

 soluble only in chloroform furnishes an indication of the extent 

 to which a bitumen has been affected by " aging." 



It has been asserted that land pitch had matured through 

 geological time and reached a condition approaching " glance 

 pitch." The word glance as applied to pitch has nothing to 

 do with its age, or with any other property except its appear- 



