The enumeration of the most important results of the astronomical and physical sciences which in the history of the Cosmos radiate toward one common focus, may perhaps, to a certain degree, justify the designation I have given to my work, and, considered within the circumscribed limits I have proposed to myself, the undertaking may be esteemed less adventurous than the title. The introduction of new terms, especially with reference to the general results of a science which p 68 ought to be accessible to all, has always been greatly in opposition to my own practice; and whenever I have enlarged upon the established nomenclature, it has only been in the specialities of descriptive botany and zoology, where the introduction of hitherto unknown objects rendered new names necessary. The denominations of physical descriptions of the universe, or physical cosmography, which I use indiscriminantely, have been modeled upon those of 'physical descriptions of the earth', that is to say, 'physical geography', terms that have long been in common use. Descartes, whose genius was one of the most powerful manifested in any age, has left us a few fragments of a great work, which he intended publishing under the title of 'Monde', and for which he had prepared hiimself by special studies, including even that of human anatomy. The uncommon, but definite expression of the 'science of the Cosmos' recalls to the mind of the inhabitant of the earth that we are treating of a more widely-extended horizon -- of the assemblage of all things with which space is filled, from the remotest nebulae to the climatic distribution of those delicate tissues of vegetable matter which spread a variegated covering over the surface of our rocks. The influence of narrow-minded views peculiar to the earlier ages of civilization led in all languages to a confusion of ideas in the synonymic use of the words 'earth' and 'world', while the common expressions 'voyages round the world', 'map of the world', and 'new world', afford further illustrations of the same confusion. The more noble and precisely-defined expressions of 'system of the world', 'the planetary world', and 'creation and age of the world', relate either to the totality of the substances by which space is filled, or to the origin of the whole universe.