443 
M 1NERA.LOG Y. 
“ From the earlieft productions of Linnfeu's to the pre- 
fent time, the word Structure has been applied, with clai- 
Jical propriety, to denote a molt Unking and charableriftic 
diftinbtion between mineral fiubftances, whether on a great 
or on a {mall fcale. Linnaeus has obferved that there are 
only three great roads which can conduct the curious tra¬ 
veller through the mineral kingdom; that of Phyfics, or 
Natural Philofophy, which treats of the obfcure genera¬ 
tion of Hones: that of Natural Hiltory, which examines 
their evident JiruClures-, and that of Chemifcry, which 
confiders their analyfis. A term thus ftri&ly appropriated, 
and, as it were, confecrated to the fcience, has therefore 
been felebled for the next characteristic fubdivifion, or 
fpecies. 
“But, as Werner and his difciples not only admit the 
various earths as fo many Genera; and their Modes, or 
the modifications of the mixtures, and even colours, as 
fo many Species; but alfo what are, with great penury 
and uncouthnels of language, ftyled Sub-fpecies, with {till 
fmaller divilions, of Varieties and Sub-varieties-, fo there 
remains a necelTity for more minute difcriminations in 
this new arrangement. In his excellent and elaborate 
fyftem of cheimftry, Dr. Thomfon feems to have hit upon 
the juft and natural term, when he ufes the word Aj'peCl 
as a chief charableriftic. The particular characters, lays 
lie, are the following: i. AfpeCt of the furface ; 2. Af- 
peCt of the fraCture ; 3. AfpeCt of the diltinCt concre¬ 
tions ; 4. General afpeCt, &c. As therefore the molt im¬ 
portant objeCt in the ltudy of minerals is to diftinguifh 
them by their external characters, and efpecially by thole 
apparent to the eye, the afpeCt becomes of fuch radical 
importance, that it may with the greatelt propriety be ad¬ 
mitted into the diftinctive nomenclature. The verb af- 
peflo lignifies to view with great attention or earneftneis, 
and affords a hint to the lludent that thefe fubdiviiions 
called alpeCts require ItriCt attention and difcrimination. 
Thus, while the Mode chiefly exprefles the difference of 
chemical compolition, &c. and the Structure the grand 
eharaCteriltic, the AlpeCt refers to more minute features, 
or fub-fpecies. 
“ The term varietij is unobjectionable, as it is equally 
applicable to objeCts of animated or inert matter; and cli- 
verjity may be ufed to imply a ltill greater difference than 
the variety prefents. A very faint fliade of difference 
might, if necelfary, be called a lineament .” 
After all, the chief utility of any fyftematic arrange¬ 
ment is'this—that we may know where to find the de- 
fcription of any fubftance we are enquiring after* and 
where to place, for the convenience of others, fuch as may 
hereafter be difcovered. We have therefore, perhaps, too 
long detained the reader from that fyftem of which our 
own opinion is already recorded at the conclufion of the 
article Linnteus, vol. xii. p. 758. 
Gmelin’s edition of the Syftema Naturae of Linnaeus 
was publilhed at Leiplic in 1793; wherein we have the 
following 
CLASSIFICATION of MINERALS. 
Minerals are divided into Five Clafies ; viz. Earths, 
Salts, Inflammables, Metals, and Petrifactions. 
CLASS I. EARTHS. 
Stones, as they evidently have their origin from har¬ 
dened compaCt Earths, into which they again moulder, 
cannot without unnatural feparation but be joined with 
them in the fame clafs. They refill fire, the greateft de¬ 
gree of which is not able to revolve any of their particles 
into vapour. They are all of them without tafte, and 
molt of them wfithout odour. This Clafs is divided into 
Seven Orders, which are fubdivided into Genera, as under. 
©rder I. Talcose, are moll of them {oft and very foft, 
principally contain Magnefia alba, and never have 
the veltiges of living bodies. They occur in primary 
mountains, more often in fecondary j fome compote 
ftrata or the principal parts of mountains, and others 
are paralitical. By the aCtion of fire they are not cal¬ 
cined, nor, except Hornblenda, ACtinotus, and ferri¬ 
ferous Albeftus.are they liquefiable, but become harder. 
This Order contains the five following Genera: 
Talcum - - Greafy to the touch. 
Serpentinus - Dry and harlh, of a fhivery fraCture, with¬ 
out luftre. 
Albeftus - - Dry, fibrous, without luftre. 
ACtinotus - Dry, Alining. 
Hornblenda - Dry, lamellous, black. 
Order II. Ponderous. Thefe exceed all others in fpe- 
cific gravity, are more ealily liquefiable by fire, always 
paralitical, never have the veltiges of living bodies, are 
loft and hardilh, and chiefly coniift of Terra ponderofa 
properly fo called. Contains the four Generaibllowing; 
Barytes - - Soluble in boiling fulphuric acid. 
Croflopetra - Not totally loluble in fulphuric acid. 
Strontia - - Soluble in marine and diluted nitric acids. 
Sydneia - - Soluble in muriatic acid. 
Order III. Calcareous. Some are formed of teftaceous 
fubftances and corals, fome are primitive, others are 
rupeltrial or parafitic, many are filled with the veltiges 
of living bodies; they are very foft, foft, and hardilh ; 
become more porous by fire; the purer ones all effer- 
vefce, and are almoft totally diifolved in nitrous acid 
or aquafortis. Contains twenty Genera: 
Creta - - - Soiling the fingers. 
Tophus - - Porous, precipitated from water. 
Spatum - - Lamellar, breaking into rhomboidal frac¬ 
tures. 
Schiftofpathum Undulately flaty. 
Inolithus 
StalaClites 
Pifolithus 
Marmor - - 
Suillus - - 
Tremolites - 
Stellaris - - 
Humus - - 
Marga - - 
Magnefiata - 
Picrofpatum 
Gypfum - - 
Hepaticus 
Fluor 
Apatites - - 
Boracites 
Fibrous, foluble entirely, with effervef- 
cence, in nitric acid. 
Precipitated from water in the air. 
Confifting of globular granulations. 
CompaCt or granular. 
Emitting an urinous fmell when fcraped. 
Radiate, partly foluble in nitric acid. 
Fibrous in a ftellate manner, eafily melt¬ 
ing in fire. 
Friable, becoming pale when dry. 
Hardening by fire, and vitrifying in a 
greater degree of heat. 
Becoming black in the fire. 
Lamellar, brittle, flowly effervefcing with 
acids. 
Calcinable with water,hardeningin the air. 
When fcraped or expofed to heat, fmelling 
like liver of fulphur. 
Infufed in hot fulphuric acid, emits a gas 
which corrodes and diflolves glafs. 
When fprinkled on red-hot charcoal,emits 
a green pholphorefcent flame; not eafily 
melted. 
Cubic, hard, femi-tranfparent. 
Order IV. Argillaceous. Of thefe fome are very foft, 
plaftic, fticking to the tongue, when moiftened give out 
a peculiar odour, hardening in the fire, and have often 
the imprellions of animals and vegetables upon them ; 
fome are foft or hardilh, and are rather liquefied than 
hardened by fire, of which the principal part are rupef- 
trial; others, though fewer in number, are hard, and 
undergo the fame change by fire. Twelve Genera are 
included in this Order, viz. 
Aluminaris - Dry and harlh, foluble almoft entirely in 
nitric acid. 
Argilla - - Greafy to the touch, plaftic, hardening by 
fire. 
Puteolana - Friable, hardening in the air when knead¬ 
ed with water and quicklime. 
Clement uni 
