This system may be erroneous, and another, more logical and more learned, may be substituted for it. But there will remain, we may hope, the synthesis which we have established from all the facts of the physical and moral order which we have collected together, the links by which we attach all the beings of creation one to another, which comprehends both the moral and organic attributes of these beings;--a vast ladder of nature, on whose steps we place everything that has life; the endless circle, in which we link all the rings of the chain of living beings. The theoretic explanation of all these facts, thus grouped, may not perhaps be accepted, but we believe that they are correctly placed in juxtaposition, and that any theory which pretends to explain the universe must be established upon the basis of that grouping. If our explanation be contested, we hope that our synthesis of facts will remain. Besides it is only thus, _i.e._, by creating a system, that the sciences, exact as well as moral, are made to progress. Chemistry was not, as some have pretended, created by Lavoisier; it was founded by Stahl, it was not the pneumatic theory of Lavoisier, but really the _system of phlogiston_ devised by Stahl, which instituted chemistry in the last century. Stahl, it is well known, had the immense merit of collecting all the facts known up to his time, into a general theoretical explanation of composing a summary of them, and of creating the _system of phlogiston_. This system was, undeniably, incorrect, but the facts which had been collected towards its construction had been perfectly well selected, and included every useful element of information or research. Thus, when ten years later than Stahl, came Lavoisier, he had only, so to speak, to turn the system of his predecessor inside out, as one turns a coat. For phlogiston Lavoisier substituted oxygen; he preserved all the facts, and changed only the explanation. Thus chemistry was founded.