276 On Crystallography. 



although^ from the manner in which they arc cut by the 

 adjoining faces, they do not appear at the first glanee to 

 be of a syinnictrical figure. Ex. Rhonibiferous quartz. 



d, Equiaxh, when it has ihe form of a rhoniboid the axis 



of which equals that of the primitive rhomboid. Ex. 

 Equiaxis earbonated lime. 



e. Inverse, when it has the form of a rhomboid the salient 



angles of which are equal to the plane angles of the 

 primitive rhomboid, and vice versa, Ex. Inverse car- 

 bonated linie. 



f, Metasiaticy i. e. transferred, when it has plane angles 



and solid angles equal to those of the nucleus which 

 are thus transferred to the secondary form. Ex. Me- 

 tastatic carbonated lime. 



g. Conlraslwg, when it has the form of a very acute rhom- 



boid, in which an inversion of angles similar to that 

 which takes place in the inverse (letter e) presents a 

 kind of contrast, in so far as it resembles in another 

 part a very obtuse rhomboid. Ex. Contrastin^j Car- 

 bonated lime. 



h. Persisfhig, is a variety of carbonated lime in which cer- 

 tain faces are cut by the adjoining faces, so that they 

 preserve the same measurcujents of angles which they 

 would have had without that, except that these angles 

 have other respective positions. Ex. Persisting car- 

 bonated lime. 



i. Analogic^ when its form presents several remarkable 

 analogies. Ex. Analogic carbonated lime. 



k. Paradoxal^ when its structure presents singular and un- 

 expected results. Ex. Paradoxal carbonated lime. 



/. Complex^ when its structure is complicated by laws not 

 very common, as when it is produced by decrements 

 some mixed and others intermediary. Ex. Complex 

 carbonated lime. 



6. Secondary for 7ns considered relatively to certain parti- 

 citlar accidents. 



The crystal is called, 



a. Transposed, when it is composed of two halves of an 

 octahedron, or of two portions of another crystal, one 

 of which .seems to have turned upon the other iai a 

 quantity cqu;al to a sixth of its circmference. Ex. 

 Transposed spinel, transposed sulphurated zinc. 



I. Hemi' trope, i. e. one-half reversed, when it is composed 

 of two halves of one and the sauic crystal, one of which 

 sccnifi to be reversed. Ex. Hemi-lrope feldspar. 

 , c. Rectangnlar, 



