And he also now exhibited the same thoroughness as before, beginning with examinations, experiments and observations, partly original, but also collected from predecessors. For he says: ›It seems to me that an infinite mass of completed experiments is a good ground to build upon, to make the trouble and expense of others serve one’s end; that is to work with the head over that which others have worked over with the hands.› (See HOLMQUIST, Op. cit. and the letter from SWEDENBORG to ERIC BENZELIUS of May 2nd, 1720, in the edition of the Acad. of Sciences, I., p. 304). The result of this period of labour SWEDENBORG embodied in a number of works, among which may especially be mentioned: ›_On the Height of Water and the Strong Tides in the Primeval World. Proofs from Sweden._›[24] SWEDENBORG here furnishes proofs that our North, in olden times, lay for the most part under deep water. And he based his deductions on a great many researches and sharpsighted observations, and wherever it was possible he tested the correctness of his conclusions by means of experiments. This is the work which J. J. BERZELIUS, A. E. NORDENSKIÖLD and A. G. NATHORST have praised so highly, and in some places it has been considered to be ›one of the most ingenious contributions to the history of geology›. SWEDENBORG also worked out during this period the great work: ›_Miscellanea observata circa res naturales et praesertim circa mineralia, ignem et montium strata_›, (printed in Leipzig 1722 and lately reprinted in the edition of SWEDENBORG’s scientific writings of the Royal Academy of Sciences, Vol. I., 1907, pp. 59-191), and finally the gigantic work: ›_Opera philosophica et mineralia_›, (published in Dresden and Leipzig, 1734, in three large folio volumes). The last work contains among other things SWEDENBORG’s cosmology, and it is here that he developes his famous _nebular theory_, which so closely reminds one of the theory worked out in later years by Kant and Laplace, that one strongly suspects that SWEDENBORG’s utterances, in one way or another, lie at the bottom of it. Concerning this work much has been written during recent years, and therefore it may be sufficient here only to refer to the statements made in regard to it by Professor S. ARRHENIUS in his introduction to the above-mentioned edition of Swedenborg’s writings, Vol. II., where he says: ›If we briefly summarize the ideas, which were first given expression to by SWEDENBORG, and afterwards, although usually in a much modified form,—consciously or unconsciously—taken up by other authors in cosmology, we find them to be the following: The planets of our solar system originate from the solar matter—taken up by BUFFON, KANT, LAPLACE, and others. The earth—and the other planets—have gradually removed themselves from the sun and received a gradually lengthened time of revolution—a view again expressed by G. H. DARWIN.