61 
and Mineralogy. 
\6. Result of these violations. — The character of a correctly 
settled natural history species, will apply to none of the above 
species admitted by German mineralogists ; and if both these 
and the others, the erroneously and the correctly settled, were in 
common submitted to a more extensive systematic treatment, 
collocations would ' arise from it, in which the properties of a 
good system must needs be wanting. A characteristic marie of 
such a defective system are in the transitions (f its species into 
one another (ii. 30.); which transitions naturally take place 
when a determinable species is split into several ; as rhomboi- 
dal quartz, rhomboidal corundum, and others, in the Werne- 
rian system. Wherever transitions of this kind are met with, 
it cannot be expected that the system will be useful in any point 
of view. 
16. The proper mode of treating those minerals which can- 
not he exhibited as independent species. — Such are the principal 
causes of the difference, in regard to its content, between this 
natural history system of mineralogy and other systems. In one 
word, none but real and accurately settled species have been ad- 
mitted in the present system. The number of species has, 
therefore, been considerably diminished. On examining the 
reasons why many of the species in other systems are not pre- 
sented in this, it will appear how minerals contained in such 
species are to be treated in regard to classification. It is neces- 
sary in fact, to unite correctly what has been incorrectly separa- 
ted. Thus quartz, iron-flint, hornstone, flint-slate, flint, cal- 
cedony, jasper, heliotrope, &c. all join themselves to the spe- 
cies rhomboidal quartz ; porcelain-earth appears under the cha- 
racter of decomposed felspar ; green- earth as an earthy varie- 
ty of talc-mica, and so on. We shall afterwards find this to 
be useful and necessary for the application of our mineralogical 
system. Indeed a correct settlement of the natural history species 
is not only the condition, on which alone a system can be con- 
sistent with itself, but also the characteristic, without which, it 
can have no application to practice, or usefulness in general. 
17. On what grounds the estimation of the mineralogical sys- 
tem rests. — According to the preceding observations, the opi- 
nion entertained of the natural history system of mineralogy will 
depend on two things; firsts That it be judged in relation to 
