In my _Lehrbuch der Naturgeschichte_, the Mineralogical and Zoological portions of which are out of print, but the Botanical still to be had (Weimar, Industrie-Comptoir, 1826), I have arranged for the first time the genera and species in accordance with the above principles, and stated everything of vital importance respecting these matters. This was the first attempt to frame a scientific Natural History, and one unto which I have remained true in my last work, the _Allgemeine Naturgeschichte_, the principles whereof I have sought to develop more distinctly and in detail in the work now before the reader. Thus then have I prosecuted throughout a long series of years one kind of principle, and worked hard to perfectionate it upon all sides. Yet, notwithstanding my endeavour to amass the manifold stores of knowledge so requisite to an undertaking like this, I could not acquire within the vast circuit that appertains thereunto, many things which might be necessary unto a system extending into all matters of detail. This it is to be hoped the reader will acknowledge, and have forbearance for the errors, against which every one will stumble who has busied himself throughout life with a single branch of the natural sciences. Natural History is not a closed department of human knowledge, but presupposes numerous other sciences, such as Anatomy, Physiology, Chemistry and Physics, with even Medicine, Geography and History; so that one must be content with knowing only the main facts of the same, and relinquishing the Singular to its special science. The gaps and errors in Natural History can therefore be filled up or removed only by numerous writers and in the lapse of time. CONTENTS. PAGE Conception of the Science 1 Division of the Science. Truth. PART I. MATHESIS 5 Nothing, § 31. Something, § 50. A. _PNEUMATOGENY_ 13 Primary Act, § 55. Primary Consciousness, § 59. God, § 61. a. Primary Rest, § 71. b. Time, § 72. Polarity, § 76. Motion, § 80. Man, § 93. c. Space, § 108. Point, Line, Surface, Globe, Rotation. B. _HYLOGENY_ 35 a. Gravity, § 148. Matter, Æther, Heavenly Bodies. b. Light, § 182. c. Heat, § 198. Fire. PART II. ONTOLOGY 49 A. _COSMOGENY_ ib. a. Rest, Centre, § 209. Motion, Line, Planets, § 215. c. Form, § 231. Planetary System, Comets. B. _STÖCHIOGENY_ 59 Condensation, § 253. Simple matters, Elements. a. Air § 282. b. Water, § 294. c. Earth, § 303. C. _STÖCHIOLOGY_ 68