The titles of these pamphlets prove that their author was no ordinary man. But the publication of them was not his only object in this visit to the continent. It was his desire to improve his practical knowledge of mining, to enable him the better to fulfill his duties as Assessor. For this purpose he left Amsterdam for Leipsic, passing through Aix-la-Chapelle, Liege, and Cologne, and visiting the different mines and smelting works which lay in his route. At Leipsic he published, in 1722, “Miscellaneous Observations connected with the Physical Sciences,” Parts I. to III.; and at Hamburg, in the same year, Part IV., principally on minerals, iron, and the stalactites in Beaumann’s cavern. The reigning Duke of Brunswick, Louis Rudolph, most hospitably received Swedenborg, defrayed his traveling expenses, and on his departure, testified his admiration of the young savant by presenting him with a gold medallion, and a weighty silver goblet. In return for these favors, Swedenborg dedicated Part IV. of his “Miscellaneous Observations” to him. In speaking of the foregoing works, it is difficult, in the few words to which we must limit ourselves, to do them the justice which their originality and daring speculation deserve. As Wilkinson remarks, “the fortress of mineral truth was the first which he approached, and with the most guarded preparation. His method was furnished by geometry and mechanics; the laws of the pure sciences were to be the interpreters of the facts of chemistry and physics. The beginning of nature, says he, is identical with the beginning of geometry; the origin of natural particles is due to mathematical points, just as is the origin of lines, forms, and the whole of geometry: because everything in nature is geometrical, everything in geometry is natural. Carrying out this theory, he seeks to define the laws of chemical essence and combination, by the truths of mathematics.” Mr. Strutt, the translator of these works into English, says: “This extraordinary attempt to bring invisible things to light, has been thoroughly justified by the success which has attended Dalton’s hypothesis, in an age better prepared for its application; and by the equally remarkable fact that the definitions given of solids, acids, and alkalies, have gradually approximated very near indeed to those which result from Swedenborg’s hypothesis. We say nothing here of a latent connection between the principle on which it is founded, and some of the results obtained by Berzelius, whose fame, as a chemist, is as wide as the civilized world.” It need only be added that M. Dumas, the French chemist, ascribes to these works by Swedenborg, the origin of the modern science of crystallography. He says, “It is to him we are indebted for the first idea of making cubes, tetrahedrons, pyramids, and the different crystalline forms, by the grouping of spherical particles; and it is an idea which has been renewed by several distinguished men, Wollaston in particular.”