96 NATURAL THEOLOGY. 



dence which the animal secretions afford of de- 

 sign, it may be derived, as has been ah-eady hint- 

 ed, from their variety, and from their appropria- 

 tion to their place and use. They all come from 

 the same blood; they are all drawn off by glands: 

 yet the produce is very different, and the differ- 

 ence exactly adapted to the work w hich is to be 

 done, or the end to be answered. No account can 

 be given of this, without resorting to appointment. 

 Why, for instance, is the saliva, which is diffused 

 over the seat of taste, insipid, w^hilst so many 

 others of the secretions, the urine, the tears, and 

 the sweat, are salt? Why does the gland within 

 the ear separate a viscid substance, which defends 

 that passage ; the gland in the upper angle of the 

 eye a thin brine, which washes the ball ? Why is 

 the synovia of the joints mucilaginous; the bile 

 bitter, stimulating, and soapy? Why does the 

 juice which flows into the stomach contain powers 

 which make that bowel the great laboratory, as it 

 is by its situation the recipient, of the materials of 

 future nutrition? These are all fair questions ; 

 and no answer can be given to them but what 

 calls in intelligence and intention. 



My object in the present chapter has been to 

 teach three things ; first, that it is a mistake to 

 suppose that, in reasoning from the appearances 

 of nature, the imperfection of our knowledge pro- 

 portionably affects the certainty of our conclusion; 

 for in many cases it does not affect it at all : se- 

 condly, that the different parts of the animal frame 



