374 IDIOPHTSICS. 



agree most nearly, or have the strongest points of resemblance, may 

 come next to each other in the system. Such a system may be 

 formed of a series of divisions, each more comprehensive than the 

 preceding, and characterized by some more general property, till we 

 come to the last and highest gradation in the scale. Thus, each 

 kingdom of nature is divided into classes, founded on the most 

 prominent distinctions ; these are subdivided into orders, founded 

 on the chief distinctions among objects of the same class ; and the 

 orders are, on the same principle, subdivided into genera; and 

 these, in like manner, are composed of species, among which all the 

 individual objects may be distributed. The most natural system of 

 classification, is, we think, that in which the chief divisions are 

 founded on the most important distinctions ; and in which objects 

 that most resemble each other, are placed nearest together. Any 

 other system, founded on minor distinctions, may be characteristi- 

 cally termed artificial. 



The laws of organic life, are, generally, not so easily tested by 

 experiment, as those of inanimate matter : hence Zoology, and 

 Botany, are sciences rather of observation, than of experiment ; 

 though often aided by the latter also. They are, however, governed 

 by definite laws, no less remarkable than those of the inanimate 

 world. Among these, we would mention, that objects which 

 resemble each other in external form, are likely also to have strong 

 resemblances of internal structure, and general properties. The 

 essential law, by which all living beings, both animals and plants, 

 are governed, is that of final causes, or conditions of existence; by 

 which, their structure and functions, must be adapted to their habita- 

 tion, and the circumstances in which they are placed. By this law, 

 beasts of prey must be swift to seize, and strong to hold, their 

 victims ; birds, that dig for insects, must have sharp and hard bills ; 

 and fishes, living under water, must have corresponding organs of 

 motion, as well as a different mode of respiration from that of 

 animals surrounded by the air alone. To trace this principle 

 throughout the living world, in plants, as well as animals, would 

 require many volumes ; and would afford to Natural Theology, the 

 strongest proofs of design, and of wisdom, in the Creation. 



The existence of final causes, and the marks of design, are also 

 numerous in the mineral, as well as the organic kingdoms of nature. 

 Thus, iron, and the more useful metals, are found the most abun- 

 dantly scattered over the earth ; while arsenic, and the other less 

 useful, or even deleterious elements, are comparatively rare. Thus, 

 again, volcanoes, which seem at first view to be agents of waste 

 and destruction, serve rather as chimneys to the subterranean fires, 

 to give vent to the confined gases, and prevent the recurrence of 

 extensive and devastating earthquakes. On the uses of Idiophysical 

 studies, we have no room to descant ; though they are numerous ; 

 not only in their applications to the various arts, to the materials for 

 which they specially relate ; but also as a means of recreation, a 

 gratification of laudable curiosity, and a clue to the designs of the 

 Great Author of nature ; whose Works, and whose Revelation, if 

 rightly interpreted, must necessarily accord with each other. 



