ATMOSPHEROLaCY. — SNOW. 477 



pleasure of the Great First Cause, whose works, even 

 the most minute and evanescent, and in regions the 

 most remote from human observation, are altogether 

 admirable. 



The various modifications of crystals may be clas- 

 sed under five general kinds or genera. 1. Lamellar. 

 2. A lamellar or spherical nucleus, with spinous ra- 

 mifications in different planes. 3. Fine spicules or six- 

 sided prisms. 4. Hexagonal pyramids. 5. Spiculae 

 having one or both extremities affixed to the centre 

 of a lamellar crystal. 



1. Lamellar c?ystals. The varieties of this kind 

 are almost infinite. They occur at all temperatures, 

 and in the greatest abundance ; and most of the spe- 

 cimens are extremely thin, transparent, and of an 

 exquisitely delicate structure. They may be sub- 

 divided into several distinct species. 



a. Stelliform ; having six points radiating from a 

 centre, with parallel collateral ramifications in the 

 same plane. This species, represented in Plate VIII. 

 Fig. 1, is the most general form met with. It va- 

 ries in size from the smallest speck, to about one- 

 third of an inch diameter. It occurs in greatest 

 profusion when the temperature approaches the 

 freezing point. 



b. Regular hexagon. This occurs in moderate 

 as well as in the lowest temperatures ; but it be- 

 comes more delicate and thin, and diminishes in size 

 as the cold increases. Some specimens consist of 

 simple transparent plates, (Plate VIII. Fig. 23.) 



