p : vi'.- ]’, 
prefented to us in a manner which affifts our 
memory, and renders our conceptions of them 
cafier, aim at earneflly adopting the noble; 
improvement, and, in order to be the more 
efteemed, we like wife always confer praife on* 
the author. 
As long as the author adheres to his fyftem,. 
and does not alter it, but only illuftrates it from 
time to time with fome additional obfervations, 
we are not only well fatisfied with him, but 
alfo often become his faithful afliftants. But if 
he, convinced of the impropriety of his method 
from its very principles, rejedls it, and prefents 
us with another new and entirely different 5 
what will then be the refult ? Or what is likely 
to happen if this is attempted by a perfon who 
is unknown, and not artful enough to feize on 
the advantages of our paffions ? 
Fur my part, I am apt to believe, that in 
the former cafe, the prefent general tade might 
be fomewhat leffened without any lofs to the 
fcience itfelf^ becaufe among the great number 
that love Natural Hiftory, there are always 
fome who embrace it when free from errors, 
and ethers, who are only fond of new reafon- 
ings and conclufions, merely becaufe they arefo. 
Thefe latter are even of fervice, and their 
party will certainly increafe in length of time. 
From this perfuafion I have ventured to 
publiili this Effay for treating Mineralogy in a 
fydematical manner ; a ftudy to which I have 
with fo much pleafure applied myfelf. It is 
not done from the defire of novelty 5 and ftill 
lefs 
