It was in the valley of the Somme (a river in the north of France) that M. Boucher de Perthes found those famous flint-axes of the rudest form. His explorations had been going on for a long time. He did all he could to bring these discoveries before the public. In the year 1836 he began to proclaim the high antiquity of man, in a series of communications addressed to the Société d'Emulation of Abbeville. To the same society, in the year 1838, he exhibited the flint-axes he had found, but without result. In 1839, he took these hatchets to Paris, and showed them to some of the members of the Institute. At first they gave some encouragement toward these researches; but this favorable feeling did not last long. In 1841 he began to form his collection, which has since become so justly celebrated. He engaged trained workmen to dig in the diluvial beds, and in a short time he had collected twenty specimens of flint wrought by the hand of man, though in a very rude state. In 1846, he published his first work on the subject, entitled "De l'Industrie Primitive, ou les Arts et leur Origine." In the following year he published his "Antiquités Celtiques et Antédiluviennes," in which he gave illustrations of these stone implements. This work attracted no attention until the year 1854, when a French _savant_, named Rigollot, made a personal examination and was successful in his search for these relicts in the neighborhood of Amiens. He was soon followed by Sir C. Lyell, Sir John Lubbock, Dr. Falconer, Sir Roderick I. Murchison, and other eminent scientists. Boucher de Perthes, continuing his researches, was rewarded, in the year 1863, by finding the lower half of a human jaw bone, covered with an earthy crust, which he extracted with his own hands from a gravel-pit at Abbeville. A few inches from it a flint hatchet was discovered. They were at a depth of fifteen feet below the surface. This bone has been called the jaw of Moulin-Quignon, and is preserved in the Museum of Natural History at Paris. The discovery of this bone produced a great sensation among English geologists. Christy, Falconer, Carpenter, and Busk went to France and examined the locality where the bone was found. They went away satisfied with both its authenticity and antiquity. Some geologists, however, doubted its authenticity; but at the present time all, or nearly all, recognize the truth of the conclusions of Boucher de Perthes. Not far from the same locality, he was again successful, in 1869, in finding a number of human bones presenting the same character as the jaw of Moulin-Quignon.