IN'TRODUCTION. 59 



The selection of an inappropriate Greek nomenclature has per- 

 haps been even more prejudicial to the last of these attempts 

 than the injudicious use of binary divisions and the excessive 

 multiplication of groups. 



The physical description of the world, considering the uni- 

 verse as an object of the external senses, does undoubtedly re- 

 quire the aid of general physics and of descriptive natural histo- 

 ry, but the contemplation of all created things, which are linked 

 together, and form one ichole, animated by internal forces, gives 

 to the science we are considering a peculiar character. Phys- 

 ical science considers only the general properties of bodies ; it 

 is the product of abstraction — a generalization of perceptible 

 phenomena ; and even in the work in which were laid the 

 first foundations of general physics, in the eight books on 

 physics of Aristotle,* all the phenomena of nature are consid- 

 ered as depending upon the primitive and vital action of one 

 sole force, from which emanate all the movements of the uni- 

 verse. The terrestrial portion of physical cosmography, for 

 which I would willingly retain the expressive designation of 

 pJujsical geography, treats of the distribution of magnetism in 

 our planet with relation to its intensity and direction, but does 

 not enter into a consideration of the ^aws of attraction or re- 

 pulsion of the poles, or the means of eliciting either permanent 

 or transitory electro-magnetic currents. Physical geography 

 depicts in broad outlines the even or irre/mlar .ifiguration of 

 continents, the relations of superficial ar_.a, auu. Uie distribution 

 of continental masses in the two hemispheres, a distribution 

 which exercises a powerful influence on the diversity of climate 

 and the meteorological modifications of the atmosphere ; this 

 science defines the character of mountain chains, which, hav- 

 ing been elevated at different epochs, constitute distinct sys- 

 tems, whether they run in parallel lines or intersect one an- 

 other ; determines the mean height of continents above the 

 level of the sea, the position of the center of gravity of their 

 volume, and the relation of the highest summits of mountain 

 chains to the mean elevation of their crests, or to their prox- 

 imity with the sea-shore. It depicts the eruptive rocks as 

 principles of movement, acting upon the sedimentary rocks by 

 traversing, uplifthig, and inclining them at various angles ; it 



Pkilosopliy of the Inductive Sciences, vol. ii., p. 277. Park, Pantolojy 

 p. 87. 



* All changes in the physical world may be reduced to motion. 

 Aristot., Phy$. Ausc, iii.. 1 and 4, p. 200, 201. Bekker, viii., 1, 8, and 

 9, p. 250, 2G2, 2G5. De Geneve et Coit., ii., 10, p. 33G. rseudo-Aris- 

 tot., De Mniido. cnp. vi., p. 398. 



