10 ON CHANGES IN THE DISPOSITION vial course to a stream, once carried that over its rocky bottom ; as that bottom, successively lowered, can often be traced on the declivities of the hills, displaying those marks of wear which have so often been idly attributed to diluvian currents. Such is all the analysis I can here afford of this par ticular branch of a subject which might well occupy a volume; but I must here notice one or two of the main consequences of this destructive power. Such are the changes of place to which rivers are subject; too often neglected or misapprehended. Among these, the change of the course of the St. Lawrence near Quebec is one of the most noted. In this way also, the Soane, which once joined the Ganges at Patna, is now many miles distant from it at that place ; while the Cosa once met it almost fifty miles lower than it does now. Thus too did Lahore lose its commerce by the alterations of the Ravee. If the Burhampooter is noted for the changes of its channel, the same is true of the Wolga and of many other rivers : while, in our own country, under other changes, the Almond, once entering the sea above Perth, now flows into the Tay, while the Earn joins it at that almost neutral point which shows,' at once, what it was and what it is destined to be. Of mere changes of level and place within the same valley, the examples are endless. If Saussurehas noted the course of the Rhine on the side of Mont Saleve, I have already pointed out a similar case in the Tay, while such examples can be traced every where. In plains, these changes are far more compli cated and extensive ; while the reason must now be obvious, in the nature of the materials of the bed, and of the declivities: and thus a great river in a great plain wanders over miles in the course of centuries, while thus also does it either multiply its channels or the reverse. All geography furnishes endless exam-