136 Chemistry. [Lecture 29. 



Even water, which some have thought consisted 

 of little spherical particles, has a disposition to 

 crystallize : its icicles are oblong masses, always 

 determined and regular in their form, and have 

 certain angles which they always affect. Thus, 

 if we expose water in a bason to be frozen, the 

 icicles always run in the same angles, and are 

 joined to each other at the same angle, not un- 

 like the vanes of a feather, or the leaves of 

 many vegetables. Sir Isaac Newton, from his 

 idea of the regular manner in which salts are de- 

 posited in rank andjile, as he called it,, thought 

 that the crystals being deposited from the water 

 in a regular manner naturally assumed regular 

 forms ; but this is not a sufficient account of the 

 matter. The crystallization of all substances 

 is, in fact, now agreed to proceed by the suc- 

 cessive deposition of moleculae, or very small par- 

 ticles, in series, the increase or diminution of 

 which by one, two, three, or more moleculae at 

 at a time may produce great variety out of the 

 same primary forms. 



Crystallization. The structure of crystallized 

 bodies has lately obtained much consideration. 

 Rome de Lisle, Gahn, and Bergman had sus- 

 pected the existence of a primitive nucleus in 

 crystallized bodies ; Hauy proceeding in this in- 

 quiry traced the laws of crystallization with 

 much success, and pointed out the modes of tran- 

 sition from primitive to secondary figures. By 

 mechanical force he thus obtained the primitive 



