•45 



as it presents itself to the senses, preserves a constant uni- 

 formity ; this source of association therefore, great and exten- 

 sive as it is, must naturally be liable to exhaustion, and it 

 appears at present to be strained very nearly to its limit. 

 But in the other case there is no asssignable boundary ; every 

 encrease of knowledge serves to shew us still more sensibly 

 than we were before aware of, how much still remains to be 

 discovered. This difference between the two is beautifully 

 expressed by Akenside — 



" Soon feeble gro\^ 

 Their impulse on the sense, while the pall'd eye 

 In vain expects it's tribute, asks in vain 

 Where are the ornaments it once admired. 

 Not so the Moral species, nor the Powers 

 Of Passion and of Thought; the ambitious mind. 

 With objects boundless as it's own desires, 

 Gan there converse, by those unfading forms 

 Touched and awakened." 



In almost every department of philosophy, natural philo- 

 sophy in particular, and in every branch of natural history, 

 the moderns have an evident and great advantage over their 

 predecessors. Hence are derived an endless multitude of 

 ideas unknown to antiquity, and various opportunities of 

 tracing out new and unexpect-ed similitudes; and whoever 

 '^^'is acquainted with the doctrine of combination* must per- 

 .'>reive, that the sphere of the imagination is encreased in a 

 ■much greater proportion than the actual number of addi- 



