In these pans the diamonds are natural in form, indicating that they have not moved since the time they were deposited. But in the beds of the rivers which have in later times worn deep ravines in the face of the country we find diamonds with abraded surfaces, having been rolled about by the torrents for indefinite periods of time. Whence come the alluvial soils and the gravel beds which cover the gem strata and completely fill up the lake depression, especially when there are no surrounding elevations to furnish disintegrated material? This serious question will naturally arise in the minds of all observers; and to answer it clearly will be a difficult task. Sometimes the thought occurs to us that much of the quartz gravel has formed in these pools at subsequent periods and has been broken up and rolled about by the waves until another stratum of alluvium has formed above it; but we will not venture to assert an opinion to this effect. Still, it is a great mystery to ascertain whence some of the quartz pebbles came from in the present elevated condition of the placers and the absence of similar rocks in the vicinity. There is another fact connected with the diamond placers which deserves consideration, and that is their great elevation above the sea level. The mines of India, Africa, and Brazil are situated at a considerable altitude above the ocean. Those of India are generally a thousand feet above the sea level; while the wonderful gem mines of the adjacent island of Ceylon, which are also true placers, occur but few feet above the line of the tides, but do not yield the diamond. It is certainly remarkable that Ceylon does not afford this gem among the great number of other precious stones. At first thought the idea occurs to the observer that as flora and fauna have their distribution according to certain elevations a similar rule may be applied to the deposition of minerals. But there are too many exceptions known to oppose this view, however pleasing the theory may be.