I do not know all the obstacles that may interfere in different countries against the efforts of the state to remove the danger. I know that in France and Germany the good intentions of the Government and Chambers will be strongly opposed by the inn-keepers; but I know, too, that no obstacles are insurmountable to a political power strongly impenetrated with love of its country. — Translated for The Popular Science Monthly from the Revue Scientifique.
By M. J. FLEURY.
AT the Universal Exposition of 1855 appeared for the first time an ingot of that silver-white metal from clay, as Sir Henry Roscoe called it. Aluminum does not seem to have attracted much attention from the public at that time. When it was exhibited again at London in 1862 and at Paris in 1867, in the shape of utensils of every sort, and jewelry, it had at first a success of curiosity, provoked by its extraordinary lightness of weight. But the difficulty of its manufacture and the consequent high price at which it was held, the delicacy of its color so easily soiled, caused it to be gradually abandoned in some of the arts, for which it was at first thought a new resource had been discovered. Its alloy with copper, aluminum bronze, notwithstanding its remarkable qualities of resistance and its beautiful golden color, hardly kept its place in industrial practice. Perhaps aluminum would have passed out of mention, except in laboratories, where its place is always marked, if its early history had not been associated with that of the progress of electricity, and if, by the aid of this new agent, its manufacture had not become so easy and so economical as to permit a considerable extension of its applications, and to provoke a revival of the hopes which had welcomed its beginning. These hopes are reasonable and are founded on the solid basis of the most serious scientific considerations. We have a right to expect much from this metal, an extensive use of it, and its substitution in many cases for others now at our service, provided it can be furnished at a price corresponding with that of other materials known in the arts.
Whether it presents itself in the earth of colors varying from yellow to brown, of which our fields are composed; or showing itself pure white, as in kaolin, clay is nothing else than a combination of alumina, silica, water, and other foreign bodies in varying proportions. Of this abundant earth, which forms approximately about half of the crust of the globe, the mass is about equally divided between silica the substance of rock crystal, and alumina;