10 INTRODUCTION. 



students is accelerated, an incalculably greater number 

 are prevented from making any progress at all. The 

 professional students ought to be to society, what 

 pioneers are to an army on its march, they should go 

 before it and clear the way, so that it may advance the 

 faster. But if the pioneers were to block up the way 

 behind them, just in order to make their own progress 

 the more rapid, it would be difficult to point out the 

 advantage that they would be to the army. 



The celebrity that has been won by system and no- 

 menclature, and the disposition which has been shown 

 to make new divisions and alter old ones, though pro- 

 bably sanctioned by the progress of discovery, has fur- 

 ther given the science of nature, as it is found in books, 

 a formidable appearance to the unscientific ; and that 

 again has been increased by the multiplicity of works 

 and systems through which one is compelled to wade, 

 before the facts that are interesting for the picture of 

 nature that they exhibit, can be collected together. 

 This, too, in England at least, is in some measure un- 

 avoidable. Works on science will not pay for the labour 

 and expense. Thus there cannot be a revision of the 

 whole subject; and the new facts come out, in the trans- 

 actions of societies and in periodical journals, in essays 

 and notices, which do not always state them with accu- 

 racy, and which seldom point out how they are to be 

 joined to the information already before the public. 

 Farther, publicity is announced by the authority of 

 names ; an influence which is always mischievous, but 

 against which there is no means or possibility of guard- 

 ing, but by the diffusion of knowledge among the pub- 

 lic generally, as they who have not the demonstrated 



