Page:Popular Science Monthly Volume 81.djvu/33

Rh

The percentage of soluble mineral matter or salts as compared to that of the bitumen is extremely small and unimportant, and plays no part in the behavior of the material industrially, since the addition of the same salts to other asphalts has been found to produce no perceptible effect upon them.

For many years Trinidad asphalt was supposed to contain a considerable amount of organic matter not of a bituminous nature, but an investigation conducted by me in 1908 showed that this really consists