and Mmerahgij. SSI 
essentially crystals, being all independent crystalline forma- 
tions (4 l.) All truly undetached compact masses are likewise 
simple, because they are all independent crystalline formations, 
which have wanted nothing but space to assume a regular form ; 
and this is the decisive property of individuals in the mineral 
kingdom. All grains, properly so called, such as those of gar- 
net, diamond, &e. are simple, being real, though not complete- 
ly formed crystals. 
8. Compound. — A mineral consisting of several homogeneous 
(25.) individuals is named a compound mineral. All compact 
minerals in distinct ccmcretions^ such even as from their smallness 
escape the eye, as in compact galena, are compounds. Of the 
same character are false crystals and minerals, appearing in 
what are called particular external forms. In the kidney- 
shaped and stalactitic forms of hematite, in the bails of radiated 
pyrites, and many others, this property is perceptible even to the 
eye. In the kidney-shaped and stalactitic forms of calcedony, the 
composition cannot so easily be distinguished. It exists, how- 
ever ; because, if minerals of this sort were simple, being pro- 
duced in free space, they would assume regular forms (7.) 
Any of the forms named particular, such as botryoidal, being 
produced in free space, is a proof of their being compound. 
9. Mixed mineral. — A mineral consisting of several dissi- 
milar (25.) individuals, is named a mixed mineral. To this 
class belong mountain-rocks, and different masses found in the 
shape of veins and beds. And as in this respect nothing de- 
pends on the size of the particles, which are mixed, iron-flint, 
heliotrope, and others, cannot be ranked among simple mine- 
rals : nor can any limit between simple and mixed minerals be 
deduced from the size of the particles which are mixed, 
10. Series of characters exist in Nature. — That certain se~ 
ries (f crystallisations exist in nature, has been already prov- 
ed by several examples, at least so that, for the present, no 
farther proof of this fact seems requisite. It is well known 
that series are also to be observed in the colours ; series in 
the shades of the different lustres ; series in the degrees of 
hardness, speciflc gravity, &c. 
