BOOKS OP INSTRUCTION. 17 



the metaphor, this flood cannot be fathomed, in all its 

 depth, by any individual of the human race; but 

 still it is a river of which all can drink ; and there is 

 no human being, be the circumstances of life what 

 they may, to whom the draught is not both necessary 

 and refreshing. Books are, as it were, the pitchers 

 in which this water of the river of knowledge is 

 fetched for the people ; and though the water itself 

 is always good, the pitcher may be naught, or its 

 contents may be foul, from being taken up in the 

 shallows where the mud is easily stirred. This, it is 

 to be feared, is the case with very many of those 

 books which profess to render the acquiring of know- 

 ledge popular and easy; and in none more so than 

 in the introductions to the different branches of 

 Natural History. 



Natural history, though, when considered in its 

 largest extent, it is the quarry from which the mate- 

 rials of all the sciences, as well as those of the arts, 

 are brought, is yet a science wholly of observation. 

 We may place the plant or the animal in peculiar 

 circumstances, and watch the results ; but still these 

 differ in kind from those which we obtain when we 

 make experiments on dead matter. Therefore, as 

 the science is wholly one of observation, all the 

 information which is offered to the public upon it, 

 should be as much as possible in accordance with 

 the mode in which knowledge occurs to us by 

 observation. 



This is necessary not merely to secure the possession 

 of the knowledge itself, but to secure that enjoyment 

 of what we know, which constitutes the real value and 

 use of knowledge. The knowledge of the plants, the 

 animals, the succession of the seasons, and of all the 

 other appearances of nature, would avail us little, if 



