While there is admittedly but scant evidence of the existence of a Stone Age in China, and still less to indicate that Chinese civilization passed through such a period, a certain number of stone artefacts, all polished, have been found within the limits of China. However, curiously enough in view of this state of things, we find that here, as almost everywhere else, these objects were popularly regarded as “thunderbolts.” Thus Chien Tsang-Ki, the author of a Materia Medica, composed in the first half of the eighth century of our era, states that objects of this kind “have been found by people who explored a locality over which a thunder-storm had swept and dug three feet in the ground”; and he adds that some of these stone implements have two perforations. They were named _pi-li-chen_, “stones originating from the crash of thunder,” and a still earlier writer, Chang (232–300 A.D.) applies a similar designation to stone axes and wedges “frequently seen among the people.” Several centuries later Shen Kun (1030–1093 A.D.) testifies that the people of his time found many stone “thunder-wedges,” in all cases after a thunder-storm; these were unperforated. It is generally believed that most of these stone implements had been made by a Tungusian tribe, akin to the Manchus.[139] This is partly due to the fact that it was natural, after a thunder-shower, for a search to be made. Then again, as thunder-showers are usually heavy rains, they were apt to loosen the soil and leave on the surface heavy objects, more especially such materials as jade, of the density of 2.9, or jadeite, of the density of 3.3. These are much heavier than the quartz, feldspar and other ingredients of the soil, which vary from 2.6 to 2.7 and are washed away. Finally, there is the natural disinclination on the part of the Chinese to dig, from their belief that it is wrong to explore the soil, and this disinclination on their part has done much to prevent a better knowledge of the Stone Age, and our knowledge of the races which must have preceded the civilization of China; many facts of mining interest have been neglected, as well, on account of this prejudice. Perhaps within the next twenty years we may learn something about a prehistoric race in China, for as traces of the existence of such races have been found in every other country of the world, there can be little or no doubt that such a race existed in China, although as yet we have no distinct evidences of it.