No land so teems with a population strong, active, and in robust health; true, it does not suit the European constitution; fever and dysentery sweep off the troops and sailors of European nations who visit the Celestial Empire for the purpose of trade or of plunder. There is a something unknown in the climate unsuitable to the European; the condition of the earth, air, and water of China, is fatal to him. In which of these does the noxious element reside--in all or in none? This is possible; but man in the meantime must decide by what he knows and sees. Here is a land teeming with life; on land, as on its waters, millions live; but that life, as regards man, is confined to the Chinese race, and is unsuited to the European; as regards the soil, manured in so strange a manner, it also is Chinese. Is it that we, generally speaking, spread the material in a liquid and vastly diluted form over the fields, whilst they manipulate and remove from it all moisture? There may be something in this, for it is known that organic compounds, above all, are most susceptible of change by the least perceivable alterations in their constituents. Agriculture is both a science and an art. “The clearing of the primeval forests of America, facilitating the access of the air to that soil, so rich in vegetable remains, alters gradually, but altogether, its constitution; after the lapse of a few years no trace of organic remains can be found in it. The soil of Germany, in the time of Tacitus, was covered with a dense, almost impenetrable forest; it must at that period have exactly resembled the soil of America, and have been rich in humus and vegetable substances; but all the products of vegetable life in those primeval forests have completely vanished from our perceptions. The innumerable millions of molluscous and other animals, whose remains form extensive geological formations and mountains, have after death passed into a state of fermentation and putrefaction, and subsequently, by the continuous action of the atmosphere, all their soft parts have been transposed into gaseous compounds, and their shells and bones, their indestructible constituents, alone remain to furnish evidence of the existence of life continually extinguished and continually reproduced.”