Photo, C. R. Toothaker, Phila. Commercial Museum.

of the water of hydration of the clay forming part of the mineral matter, which was lost on ignition after the removal of the bitumen by solvents, and that, as a matter of fact, there is practically nothing of the nature of the organic matter not bitumen which has heretofore been attributed to Trinidad asphalt.

In direct contrast to this acid water is that which rises with the soft pitch in the center of the lake, which is alkaline in reaction, and has the following composition: