various important subjects in Mineralogy. 285 
from the character and the general description. It is not capable^ 
of being analysed, or reduced to single characteristic terms or 
marks ; and hence it should be considered only as a whole, tak- 
ing it in its general compass. An example, taken from the 
species of Man, which is necessarily familiar to every body, may 
serve to illustrate this. If we speak of man in general, we do 
not reflect upon any individual, or a single relation of size, co- 
lour, countenance, &c. ; nor upon the European, the African, 
&c. ; still less upon the Englishman, the German, the French- 
man, the Spaniard, & c. ; but, as it were, upon a mean term of 
them all, which can never be represented by any individual, but 
necessarily requires the whole species. In like manner, the re- 
presentation of the species of Augite (paratomous augite-spar), 
does not apply solely to diopside, or to augite, or sahlite, or 
omphazite, or to any other particular variety, but to the whole 
species, which can never be observed as a single body in nature. 
We may easily conceive that these representations are not ex- 
actly the same in every individual ; nay, that there are not per- 
haps two people that possess them precisely similar ;-—-for who 
could determine this point ? They must therefore be different 
from the idea of a circle or a square, which are not different in any 
two individuals. But nothing depends upon this perfect equa- 
lity, because there are resources in Natural History that are in- 
dependent upon this difference of conception in different persons, 
not only for deciding in what species a particular individual 
should be included, but also for producing the general concep- 
tion of the species, and of which we shall have occasion to speak 
more at large. One thing only remains to be observed in this 
place, which is, that these representations of the species cannot 
be obtained by way of abstraction, — for, by that process, every 
thing would either be lost, or, at least, so little would be left, 
that it could be of no further service in Natural History. 
The comparison, in regard to the natural-historical similarity, 
must now be referred to these original representations or con- 
ceptions of the species. If these are found to coincide to a cer- 
tain extent, and in the highest degree distinguishable, in two or 
more species, then these species form a Genus, or belong to a 
genus, of which there is now formed another representation of 
VOL. XIV. NO. 28. APRIL 1826. 
x 
