36 FINAL CAUSES. 



the same efifects. Could we resist the persuasion that the 

 Artificer of this insect, when forming it of this shape, and 

 providing it with these paddles, had the same mechanical 

 objects in view? Shall we not be confirmed in this idea 

 on finding that these paddles are constructed with joints, 

 that admit no other motion than that of striking against the 

 water, and of thus urging forwards the animal in its passage 

 through that dense and resisting medium? Many aquatic 

 animals are furnished with tails which evidently act as rud- 

 ders, directing the course of their progressive motion through 

 the fluid. Who can doubt but that the same intention and the 

 same mechanical principles which guide the practice of the 

 ship-builder, are here applied in a manner still more refined 

 and with a master's hand? If Nature has furnished the nau- 

 tilus with an expansible membrane, which the animal is 

 able to spread before the breeze, when propitious, and by 

 means of which it is wafted along the surface of the sea, but 

 which it quickly retracts in unfavourable circumstances, is 

 not her design similar to that of the human artificer, when 

 he equips his bark with sails, and provides the requisite 

 machinery for their being hoisted or furled with ease and 

 expedition? 



The maker of an hydraulic engine places valves in par- 

 ticular parts of its pipes and cisterns, with a view to pre- 

 vent the retrograde motion of the fluids which are to pass 

 through them. Can the valves of the veins, or of the lym- 

 phatics, or of the heart have a difierent object: and are they 

 not the result of deliberate and express contrivance in the 

 great Mechanist of the living frame? 



The knowledge of the laws of electricity, in its difierent 

 forms, is one of the latest results which science has revealed 

 to man. Could these laws, and their various combinations, 

 have been unknown to the Power who created the torpedo, 

 and who armed it with an energetic galvanic battery, con- 

 structed upon the most refined scientific principles, for the 

 manifest purpose of enabling the animal to strike terror into 

 its enemies, and paralyze their efforts to assail it. 



Does not the optician, who designedly places his convex 



