TABLES 
OF THE 
COMBINATIONS OF CRYSTALS 
WITH THE PARALLELISMS RESULTING, 
AND THE 
CANONS OF DERIVATION. 
Tue combinations of faces which can occur in crystals, are, in the 
following pages, tabulated and classified according to the parallelisms and 
other relations of edges which they exhibit. And these relations thus 
afford the means of recognizing the class to which the forms belong, and 
consequently the laws by which the faces are derived. 
The fourth column contains the symbols for these combinations, 
according to the notation which has been explained. 
The last column, which is on the opposite page, contains the cor- 
responding properties; and these are to be looked for in a given crystal, 
in order to determine its class. 
These combinations are exhibited in the figures in the Plates, where 
they are numbered according to the order of the classes in the third column : 
the letters in the figures refer to the second column. 
In the second column are examples, in particular minerals, of these 
combinations; with references to the figures by which they are illustrated 
in Professor Mohs’s Treatise on Mineralogy; and the nomenclature of 
that work is adopted in designating these minerals. 
The frst column contains such other remarks as may be useful for 
distinguishing and discriminating different forms. 
Besides the theorems (4), (B), &c. the subsidiary theorems are referred 
to by the letters (S. 7’) 
