The inventor of a particular weapon, or certain furnishings, or tools, had all possible rights in the constructing and possession of these weapons, furnishings, or tools; but these rights could not be extended to the hindering of his neighbours from making tools, furnishings, or weapons, in every way similar. If the community had admitted an exclusive right in these inventions, it would have died in its germ, civilization would have been a dead letter, and man would have been unable to fulfil his destiny. Thus far, then, there was not, nor could be in principle, any question of exclusive right of invention. This right was only thought of when all notions of social right had been obscured by laws which, like that of Henry II., declared that the right of labour belonged to the Crown, and when there had grown up the idea of licensing labour and granting exclusive privileges for its exercise. The institution of the pretended property in inventions was a retaliation against the suppression of the abusive right of masterships and corporations. II. Doubtless invention, as M. le Hardy de Beaulieu remarks, consists in the discovery of a new scientific principle; but we cannot admit, with the learned Professor, that the new application of a principle already known, that the discovery of a natural agent hitherto unknown, or of new properties or other modes of action of natural agents, or of materials previously discovered, are inventions. It is probable that coal was known long before any one thought of putting it in a stove to be used as fuel. It is certain that stone was known long before any one thought of employing it in the construction of walls. To pretend that the discovery of the combustible quality of coal, or of the use to which stone might be put, gave a right to the discoverer to exact from his neighbours the payment of a royalty before employing this fuel, or this material for construction, is also to grant that he who, centuries before, had thought of burning wood to warm himself, or of seeking the shelter of a cave, ought also to be recompensed for the trouble he had in discovering, appropriating, and working out either this source of heat or this means of shelter. Invention, we acknowledge, consists in the discovery of a new scientific principle; it can often place, as M. le Hardy de Beaulieu says, new gratuitous forces at the disposal of the community; but does it follow that the inventor has an exclusive right in the property of this discovery? We think not. The inventor of the compass, whoever he was, has rendered an immense service to the community; but could his invention be claimed as private property? Does it not, on the contrary, enter with perfect justice into the public domain?