128 REVERSION, NOT A LAW, S€I GENERIS. 



evolved one from another; but were evolved, each, 

 from an independent centre. Crystals also, may be 

 modified, as are organic beings under nature ; and, like 

 them, such modification will be injurious to the coor- 

 dination of their forces. They will also regain a lost 

 edge, as well as organic beings will acquire, by rever- 

 sion, a lost character; and, in proportion as they repair 

 their lost edges, will their coordination approximate its 

 normal type; the same as will the coordination of an 

 organism be repaired, in proportion as Reversion re- 

 stores the lost characters. Although you may trun- 

 cate each individual crystal, after it has attained its full 

 integrity, you do it only in derogation of its coordina- 

 ting, crystallogenic force. 



These crystals occur of all sizes, from the merest 

 microscopic point, to a yard, or more, in diameter, and 

 of all degrees of complexity. A single crystal of 

 quartz, now at Milan, is three- and a quarter feet long, 

 and five and a half feet in circumference, and its weight 

 is estimated at 870 pounds. Each mineral has its 

 own mode of crystallization, by which it may be dis- 

 tinguished, just as one distinguishes a genus of plant, 

 by its characters, and mode of growth. And if: is 

 known, at once, to a mineralogist, of what mineral, a 

 crystal is formed, wherever it may be found, by its 

 angles, and by peculiarities of internal structure, such 

 as its lines of cleavage. A variety of forms is often 

 presented by a single mineral ; and this variety may be 

 very great, as with Calc-spar which is found in double 

 pyramid, in prisms, and in rhombohedrons; and so 

 with other species, as they are called; althqugh only 



