Until the beginning of the present century, the protective function of the forest had played no role in the arguments for state interference, but just about the beginning of the century cries were heard from France that, owing to the reckless devastation of the Vosges and Jura Alps by cutting, by fires and over-grazing, brooks had become torrents, and the valleys were inundated and covered by the debris and silt of the torrents. A new aspect of the results of forest devastation began to be recognized, which found excellent expression in a memoir by _Moreau de Jonnès_ (Brussels, 1825), on the question “What changes does denudation effect on the physical condition of the country.” This being translated into German by Wiedenmann, was widely spread, being interestingly written, although not well founded on facts of natural history and physical laws. Nevertheless, sufficient experience as regards the effect of denudation in mountainous countries had also accumulated in southwest Germany and in the Austrian Alps, and the necessity of protective legislation was recognized. This necessity first found practical expression in the Bavarian law of 1852, in Prussia in 1875, and in Württemberg in 1879. But a really proper basis for formulating a policy or argument for protective legislation outside of the mountainous country is still absent, although for a number of years attempts have been made to secure such basis. 8. _Forestry Science and Literature._[5] [5] The necessarily brief statements which are made under this heading presuppose knowledge of the technical details to which they refer. In this short history it was possible only to sketch rapidly the development of the science in terms familiar to the professional man. The habit of writing encyclopædic volumes, which the Cameralists and learned hunters had inaugurated in the preceding century, continued into the new one, and we find _Hartig_, _Cotta_, _Pfeil_ and _Hundeshagen_ each writing such encyclopædias. _Carl Heyer_ began one in separate volumes, but completed only two of them. Even an encyclopædic work in monographs by several authors was undertaken as early as 1819 by _J. M. Bechstein_, who with his successors brought out fourteen volumes, covering the ground pretty fully. While in the earlier stages the meager amount of knowledge made it possible to compress the whole into small compass, the more modern encyclopædias of _Lorey_, _Fürst_ and _Dombrowski_ arose from the opposite consideration, namely, the need of giving a comprehensive survey of the large mass of accumulated knowledge.