MEMOIR OF THOMAS SAY. XV. 



ral history require, is much greater than what is commonly 

 imagined ; and the difficulty of accurately distinguishing 

 specific characters is known only to those who are familiar 

 with these matters. " Specific characters," says Wildenow, 

 "to be perfect, must he common to no other of the genus." 

 It hence follows, that the describer's knowledge must not- 

 only be positive but relative, as no one can define systemati- 

 cally, without knowing what are the characteristics of other 

 species of the same genus. 



This difficulty was probably the cause of the want of 

 technical precision above referred to ; as from Mr. Say's 

 anxiety to prepare some of his papers for the press, in order 

 to secure the honour of discovery, he did not allow himself 

 that time in their composition which, from their nature, they 

 required. 



With respect to the literary part of Mr. Say's labours, it 

 has been conjectured that posterity will not award him that 

 praise to which his talents and zeal should seem to entitle 

 him. No natural historian can reasonably expect durable 

 celebrity, without having established his reputation upon 

 the foundation of polite learning. The ponderous tomes of 

 the elder naturalists of Europe, sought after, not for their 

 intrinsic value, but for their rarity, lie neglected in some 

 obscure nook of our libraries ; their erudite authors, dis- 

 daining a sacrifice to the Muses, received no inspiration 

 from the sacred mount, and they are fast passing into ob- 

 livion. Whereas Buffon, whose acquirements in some 

 branches of natural history were so very slender, that many 

 writers refuse to admit his authority, has, nevertheless, 

 erected a monument to the glory of the French language 

 more durable than brass or marble. Where is the English 

 student who has not refreshed his mind with the graphical 

 descriptions, and the chaste language, of the "Animated 

 Nature" of Goldsmith, although it is well known that this 

 illustrious writer had little knowledge of natural history, 

 except what was derived from books. 



Had our lamented friend not misemployed his youth, he 



