When we compare the relations of the alluvium of the rivers in valleys with those of the loose blocks, their similarity must strike every one. Thus, rolled masses are seldom deposited in those places where a river forces its way through a narrow passage; but where an expansion takes place, owing to the distance of the banks increasing, the rolled masses are sometimes accumulated in whole banks. The same loose blocks seldom occur in the narrow passages of the transverse valleys in the Alps; but as soon as widenings of the valleys take place below these narrowings, the blocks occur in abundance. If, during a flood, a rupture takes place in the banks of a river, where it is contracted, a part of the stream will flow out by the lateral opening, and carry along with it rolled masses, even when the opening in the bank does not reach to the bottom of the bed of the river; for the mountain stream, loaded with boulders, carries them not merely in single masses along its bottom, but the flood-water of the stream generally attacks large sandbanks, or older beds of rolled masses, and carries along with it, accompanied with a terrible noise, whole masses, forces them over the lower banks, or through the chasm in the bank, and often deposites them several feet high, on an immediately succeeding widening of the river’s course. In the same manner, we observe loose blocks deposited on high situations in the lateral valleys of the great transverse valleys, and dispersed over the passes into the neighbouring valleys. The height of the lateral deposites of loose blocks, and their position in the passes, and their passing into neighbouring valleys, are facts which assist us in judging of the extent of the power that may have acted during their transportation. The striking agreement observable in the phenomena of the distribution of the loose blocks from the interior Alpine valleys to the interior valleys of the Jura, with those in the rolled masses carried along by rivers, must lead every one, who reflects on this interesting phenomenon, to the hypothesis, that these blocks may have been deposited in their present situations by an overwhelming flood, which burst from the Alps. It is true that this opinion is liable to many objections; but still it contains a more plausible explanation of the phenomenon than any other with which we are acquainted. The loose blocks, in the different river-districts, being in general separated from each other, or if any intermixture takes place of the rolled masses of one valley with that of another, it being only on their edges, it is highly probable that the floods which burst from these valleys, and carried along with them the masses of rocks, may have been simultaneous, by which the flow of the one basin would bound and limit that of the other, and thus prevent the water-flood of one basin flowing into the neighbouring ones.