266 TEIIMINOLOGT. . 188. 



preferable, in as much as by itself it intimates, that they 

 can only appear in compound minerals. It conveys like- 

 wise more readily the idea of individuals, since distinct 

 concretions might also refer to simple minerals. The idea 

 of the individuality of minerals is one of those which have 

 for a long time remained unsettled, and yet the possibility 

 of a scientific mineralogical method greatly depends upon 

 this idea. 



The particles of composition are distinguished, according 

 to their length, breadth, and thickness, into granular, colum- 

 nar, and lamellar particles of composition. The granular 

 particles have all their dimensions nearly equal, or at least 

 not very different. We may omit here all those distinc- 

 tions which mineralogists have introduced, in respect to 

 the particular shape of these granular particles, because 

 this being not a regular one, it signifies but little in the mi- 

 neral kingdom. Granular limestone (rhombohedral Lime- 

 haloide), Coccolite (paratomous Augite-spar), dodecahedral 

 Garnet, &c. contain many examples of granular particles 

 of composition. 



In the columnar particles the length is greater than both 

 breadth and thickness. Sometimes they are rather thicker 

 on one end ; sometimes also thev are broad. This, how- 

 ever, for the above mentioned reasons, does not occasion 

 any farther difference. As to their direction, they are 

 either parallel or diverging. Examples of columnar par- 

 ticles of composition we find in rhombohedral Lime-haloide, 

 in a variety of prismatic Topaz called Picnite, in rhombo- 

 hedral and prismatic Iron-ore, &c. 



In the lamellar particles, the length and breadth surpass 

 the thickness. These likewise are sometimes thicker on 

 one end, and thus approach to the columnar particles of 

 composition ; in general, these three kinds of particles of 

 composition are not contained within precise limits, but 

 they pass insensibly into each other. There are straight 

 and curved lamellar particles of composition. The latter 

 are not individuals, but of themselves they are already 

 composed, which distinguishes them from the former, even 



