m 
and Mineralo^i/. 
simple forms. If the homologous surfaces be enlarged succes- 
sively, one of those simple forms will arise after the other (1. 6.) 
An individual appearing in a compound form may therefore 
be considered as a double, triple, quadruple individual, accor- 
ding as two, three, four, &c. simple forms are included in the 
combination. 
16. Continuation, and other protfa. — These dilferent indivi- 
dual forms belonging to the same series, are connected with the 
resulting form of the combination. Hence different indivi- 
duals, whose forms are members of one series, may completely 
agree in their remaining characters. This is not the only mode 
in which the same fact may be established. It will not be diffi- 
cult to find individuals in calcareous-spar, fluor-spar, and other 
species, which completely agree in colour, transparency, lustre, 
hardness, specific gravity, &c. whose forms, at the same time, 
are not similar, but merely terms of the special series to which 
they belong. However, as the proof, conducted in this manner, 
applies to those species only by means of which it has been 
obtained ; it is better, for the sake of universality, to employ 
the combinations, which (16.) constitute a perfect general re- 
lation to the mineral kindgom. 
17. The proof serves for all series of characters, — What 
has now been proved with respect to series of crystallisations, 
namely, that different terms of such series, having a perfect 
agreement in their rema'ming characteristics, may he united in 
minerals ; is also true with respect to the terms in any other 
series of characters. In the latter case, however, the proof 
can only be obtained by considering each particular case ; and 
the reason is, that such series of characters admit not of ma- 
thematical treatment, by which alone universal properties can 
be established. 
18. Individuals of themselves 'not uniform, brought under 
the conception of miiformity.-^Yl\\m individuals agree as to 
all their characters but one, if the differences of that one are 
members of the same "series, it follows, from what has been 
said (16.), that, instead of those dissimilar members, one and 
the same may be substituted in each individual ; by which 
means those individuals are made to agree in all respects ; that 
is to say, they become uniform (18.) In a grt\‘it number of 
