SYSTEMATIC PETROGRAPHY 343 
essential element of the species in the animal or vegetable king- 
dom was its power to ‘produce a similar progeny.” 
Dr. Jameson tells us [remarks Pinkerton] that there is in fact but ove 
species in mineralogy, namely, the globe; but even this may be doubted till 
it shall have produced another, at least as round and as wicked. 
Admitting as appropriate the fundamental division of natural 
history into three kingdoms, the animal, vegetable, and mineral, 
Pinkerton ingeniously draws a distinction. 
In the two former [he remarks] the kingdom consists of living subjects, 
who, of course, may be well considered as divided into classes, orders, genera, 
and species; but in the mineral kingdom the territory alone constitutes the 
subject of discussion. 
But the very term mineral kingdom may of itself lead to a new and more 
proper nomenclature; for as akingdom may be regarded as either vivified 
with animal and vegetable life, or as an inert tract of country, with certain 
geographical, chorographical, and topographical divisions; so the latter point 
of view can alone apply to mineralogy, while the former belongs to zodlogy 
and botany. 
What is more usual than the division of a kingdom into provinces, dis- 
tricts, domains, etc.? I would propose, therefore, in the present advanced 
state of the science, that the mineral kingdom be considered as divided into 
three Provinces: 
I. Petralogy, or the knowledge of rocks, or stones which occur in large 
masses. 
2. Lithology, the knowledge of gems and small stones. 
3. Metallogy, or the knowledge of metals. 
Petralogy, a Province of mineralogy [is then | divided into twelve Domains ; 
of which the first six, being distinguished by the substances themselves, may 
be called sudstantial, while the remaining six, being distinguished by circum- 
stances or accidences of various kinds, may be called czrcumstantial or acct- 
dential, but this last division is of little moment. 
The six ‘‘substantial’’ domains of Pinkerton are: 
. The Siderous, in which iron predominates. 
. The Siliceous. : 
. The Argillaceous. 
The Magnesian. 
. The Calcareous. 
. The Carbonaceous. 
An fFwWN HA 
The ‘‘accidential’’ domains are: 
7. The Composite. 
