308 NATURAL THEOLOGY. 



undulations excited by the surrounding body are 

 carried to the organ ; that a communication is 

 formed between the object and the sense ; which 

 must be done, before the internal machinery of the 

 ear, subtile as it is, can act at all. 



III. The organs of voice and respiration are, 

 no less than the ear, indebted, for the success of 

 their operation, to the peculiar qualities of the 

 fluid in w^iich the animal is immersed. They, 

 therefore, as w^ell as the ear, are constituted upon 

 the supposition of such a fluid, i. e., of a fluid w ith 

 such particular properties, being always present. 

 Change the properties of the fluid, and the organ 

 cannot act ; change the organ, and the properties 

 of the fluid would be lost. The structure, there- 

 fore, of our organs, and the properties of our at- 

 mosphere, are made for one another. Nor does it 

 alter the relation, whether you allege the organ to be 

 made, for the element (which seems the most natu- 

 ral way of considering it,) or the elements as pre- 

 pared for the organ. 



IV. But there is another fluid with which w'e 

 have to do; with properties of its own ; wdth laws 

 of acting, and of being acted upon, totally diflerent 

 from those of air and water: and that is light. 

 To this new, this singular element — to qualities 

 perfectly peculiar, perfectly distinct and remote 

 from the qualities of any other substance with 

 which we are acquainted — an organ is adapted, 

 an instrument is correctly adjusted, not less pecu- 

 liar amongst the parts of the body, not less singu- 



