X INTRODUCTION. 



to investigate the mutual agencies of the elementary principles of mat- 

 ter .upon one another, their composition, and the laws by which they 

 are regulated. These divisions of the great field of Natural Science 

 have, from the universality of their influence, been called General 

 Physics; while Natural History, in its limited sense, and as confined 

 to the examination of what have been called the three kingdoms of 

 Nature, viz: the Animal, Vegetable, and Mineral, has received the 

 name of Particular Physics. Natural History, besides, is distinguished 

 from the other branches of science now named in this, that while Dy- 

 namics is a science chiefly of calculation, and Chemistry of experi- 

 ment, the basis of this science rests chiefly on observation. 



In the limited sense in which Natural History is thus to be under- 

 stood, as confined to the three great divisions of Animals, Vegetables, 

 and Minerals, a System of Nature is a grand catalogue of the objects 

 in these kingdoms, in which each individual has a distinctive charac- 

 ter and an appropriate name. These individuals, for the sake of ar- 

 rangement, are collected into groups, which have something in com- 

 mon, and which are termed Genera; genera are further combined into 

 other groups, which form in systems what are called Orders; and or- 

 ders are finally arranged under one great head, which is termed a 

 Class. This scale of divisions, of which the highest contains the least, 

 is, as Baron Cuvier remarks, a kind of dictionary, where the properties 

 of things are investigated to discover their names, and which reverses 

 the usual order of such works, where the names are indicated as de- 

 tailing the qualities of the things named. 



But though method and arrangement form the first step to the know- 

 ledge of the numerous objects which claim the attention of the Natu- 

 ralist, Natural History is by no means confined to a list of names. If 

 the method be a good one, and the subdivisions arranged conformably 

 to the fundamental and natural connections of bodies, the very arrange- 

 ment and classification of names of beings which have something in 

 common, leads to the knowledge of their conneciion and dependence 

 upon one another, and to their comparative importance in the scale of 

 existence. Were it possible to arrange all the classes of organized and 

 inorganized existence in such a manner that the individuals of the 

 same genus should be more nearly connected with that genus than 

 with any other — the genera of the same order more nearly connected 

 with that order than with all the other orders, and so on, — little more 

 would be necessary to make the method, so far as depends on arrange- 

 ment, complete. But it has not hitherto been found in practice, that 



