I HAVE endeavored, in the preceding part of my work, to explain and illustrate, by various examples, how the enjoyments presented by the aspect of nature, varying as they do in the sources from when they flow, may be multiplied and ennobled by an acquaintance with the connection of phenomena and the laws by which they are regulated. It remains, then, for me to examine the spirit of the method in which the exposition of the 'physical description of the universe' should be conducted, and to indicate the limits of this science in accordance with the views I have acquired in the course of my studies and travels in various parts of the earth. I trust I may flatter myself with a hope that a treatise of this nature will justify the title I have ventured to adopt for my work, and exonerate me from the reproach of a presumption that would be doubly reprehensible in a scientific discussion.
Before entering upon the delineation of the partial phenomena p 57 which are found to be distributed in various groups, I would consider a few general questions intimately connected together, and bearing upon the nature of our knowledge of the external world and its different relations, in all epochs of history and in all phases of intellectual advancement. Under this head will be comprised the following considerations:
1. The precise limits of the physical description of the universe, considered as a distinct science.
2. A brief enumeration of the totality of natural phenomena, presented under the form of a 'general delineation of nature.'
3. The influence of the external world on the imagination and feelings, which has acted in modern times as a powerful impulse toward the study of natural science, by giving animation to the description of distant regions and to the delineation of natural scenery, as far as it is characterized by vegetable physiognomy and by the cultivation of exotic plants, and their arrangement in well-contrasted groups.
4. The history of the contemplation of nature, or the progressive development of the idea of the Cosmos, considered with reference to the historical and geographical facts that have led to the discovery of the connection of phenomena.
The higher the point of view from which natural phenomena may be considered, the more necessary it is to circumscribe the science within its just limits, and to distinguish it from all other analogous or auxiliary studies.
Physical cosmography is founded on the contemplation of all created things — all that exists in space, whether as substances or forces — that is, all the material beings that constitute the universe. The science which I would attempt to define presents itself, therefore, to man, as the inhabitant of the earth, under a two-fold form — as the earth itself and the regions of space. It is with a view of showing the actual character and the independence of the study of physical cosmography, and at the same time indicating the nature of its relations to 'general physics, descriptive natural history, geology, and comparative geography', that I will pause for a few moments to consider that portion of the science of the Cosmos which concerns the earth. As the history of philosophy does not consist of a mere material enumeration of the philosophical views entertained in different ages, neither should the physical description of the universe be a simple encyclopedic compilation of the sciences we have enumerated. The difficulty of defining the limits of intimately-connected studies has been increased, because for centuries it has been customary to designate various branches p 58 of empirical knowledge by terms which admit either of too wide or too limited a definition of the ideas which they were intended to convey, and are, besides, objectionable from having had a different signification in those classical languages of antiquity from thish chey have been borrowed. The terms physiology, physics, natural history, geology and geography arose, and were commonly used, long before clear ideas were entertained of the diversity of objects embraced by these sciences, and consequently of their reciprocal limitation. Such is the influence of long habit upon language, that by one of the nations of Europe most advanced in civilization the word "physic" is applied to medicine, while in a society of justly deserved universal reputation, technical chemistry, geology and astronomy (purely experimental sciences) are comprised under the head of "Philosophical Transactions."
An attempt has often been made, and almost always in vain, to substitute new and more appropriate terms for these ancient designations, which, notwithstanding their undoubted vagueness, are now generally understood. These changes have been proposed, for the most part, by those who have occupied themselves with the general classification of the various branches of knowledge, from the first appearance of the great encyclopedia ('Margarita Philosophica') of Gregory Reisch,* prior of the Chartreuse at Freiburg, toward the close of the fifteenth century, to Lord Bacon, and from Bacon to D'Alembert; and in recent times to an eminent physicist, Andre Marie Ampere.**
[footnote] *The 'Margarita Philosophica' of Gregory Reisch, prior of the Chartreuse at Freiburg, first appeared under the following title: Aepitome omnis Philosophiæ, alias Margarita Philosophica, tractans de omni generi scibili. The Heidelberg edition (1486), and that of Strasburg (1504), both bear this title, but the first part was suppressed in the Freiburg edition of the same year, as well as in the twelve subsequent editions, which succeeded one another, at short intervals, till 1535. This work exercised a great influence on the diffusion of mathematical and physical sciences toward the beginning of the sixteenth century, and Crasles, the learned author of 'L'Aperçu Historique des Methodes en Géometrica' (1837) has shown the great importance of Reisch's 'Encyclopedia' in the history of mathematics in the Middle Ages. I have had recourse to a passage in the 'Margarita Philosophica', found only in the edition of 1513, to elucidate the important question of the relations between the statements of the geographer of Saint-Die, Hylacomilus (Martin Waldseemuller), the first who gave the name of America to the New Continent, and those of Amerigo Vespucci, Rene, King of Jerusalem and Duke of Lorraine, as also those contained in the celebrated editions of Ptolemy of 1513 and 1522. See my 'Examen Critique de la Gegraphie du Nouveau Continent, et des Progres de l'Astronomie Nautique aux 15e et 16e Siecles', t. iv., p. 99-125.