xiv PREFACE, 
veau, when reforming the nomenclature of Chemistry, the sound- 
ness of which Dugald Stewart has recognised : — “‘ Ve faites grace 
aaucune dénomination impropre. Ceux qui savent déja, entendront 
toujours ; ceux qui ne savent pas encore, entendront plutot.” 
Throughout the whole publication, wherever any fact of import- 
ance not depending on their own authority is mentioned, a refer- 
ence to the source whence it has been derived is generally given ; 
so that, if the work should have no other value, it will possess that 
of saving much trouble to future inquirers, by serving as an index 
to direct them in their researches. 
The Authors are perfectly sensible that, notwithstanding all 
their care and pains, many imperfections will unavoidably remain 
in their work. There is no science to which the adage, Dies diem 
docet, is more strikingly applicable than to Natural History. New 
discoveries are daily made, and will be made, it is probable, to the 
end of time; so that whoever flatters himself that he can produce 
a perfect work in this department, will be miserably disappointed. 
The utmost that can reasonably be expected from naturalists, is to 
keep pace with the progress of knowledge; and this the authors 
have used their best diligence to accomplish.’ Every new year since 
they took the subject in hand, up to the very time when the first 
sheets were sent to the press, numerous corrections and alterations 
have suggested themselves ; and thus they are persuaded it would 
be were they to double the period of delay prescribed by Horace. 
But Poetry and Natural History are on a different footing; and 
though an author can plead little excuse for giving his verses to 
the world while he sees it possible to polish them to higher excel- 
lence, the naturalist, if he wishes to promote the extension of his 
science, must be content to submit his performances to the public 
disfigured by numerous imperfections. 
In the introductory letter several of the advantages to be de- 
rived from the study of Entomology are pointed out; but there is 
one which, though it could not well have been insisted upon in 
that place, is too important to be passed over without eMac 
value in the education of youth. 
All modern writers on this momentous subject unite in re- 
commending in this view Natural History; and if “the quality 
of accurate discrimination, the ready perception of resemblances 
