NATURAL THEOLOGY. 93 



ration of art wherewith exactly to compare all 

 this, for no other reason, perhaps, than that all 

 operations of art are exceeded by it. No chemi- 

 cal election, no chemical analysis or resolution of 

 a substance into its constituent parts, no mechani- 

 cal sifting or division that we are acquainted with, 

 in perfection or variety come up to animal secre- 

 tion. Nevertheless, the apparatus and process are 

 obscure, not to say absolutely concealed from our 

 inquiries. In a few and only a few instances, we 

 can discern a little of the constitution of a gland. 

 In the kidneys of large animals, we can trace the 

 emulgent artery dividing itself into an infinite 

 number of branches ; their extremities every 

 where communicating with little round bodies, in 

 the substance of which bodies the secret of the 

 machinery seems to reside; for there the change 

 is made. We can discern pipes laid from these 

 round bodies towards the pelvis, which is a basin 

 within the solid of the kidney. We can discern 

 these pipes joining and collecting together into 

 larger pipes ; and, when so collected, ending in 

 innumerable papillee, through which the secreted 

 fluid is continually oozing into its receptacle. This 

 is all we know of the mechanism of a gland, even 

 in the case in which it seems most capable of 

 being investigated. Yet to pronounce that we 

 know nothing of animal secretion, or nothing sa- 

 tisfactorily, and with that concise remark to dismiss 

 ihe article from our argument, would be to dis- 

 pose of the subject very hastily and very irration- 



