SXOW CRYSTALS. 



r.v WILSON A. r.i:NTLi:v 



Ckystals constitute a most interesting and import- 

 ant part of Nature. Their manner and habits of 

 growth are marvellous and full of interest. The 

 seeming similarity of some of 

 their forms and \va\- of growing, 

 to certain of the lower organisms, 

 and to certain vegetal forms, their 

 power of increasing in size and of 

 repairing broken parts, and so on. 

 have almost led some to consider 

 them as constituting the first span 

 bridging the vast gulf existing 

 between the inorganic and organic- 

 kingdoms. 



However this may be, there 

 is certainly a great difference 

 between plants and flowers, and 

 crystals. Plants and all organic 

 life grow from within outwarti. 

 and have their forms pre-limited, 

 as they reach a certain size and 

 then cease growth. 



Crystals, on the other hand, 

 grow wholly from without, by 

 deposition, and properly never 

 reach maturity, as they are always 

 in a state of incompleteness, and 

 ever ready to resume growth 

 whenever fresh sujiplies are fur- 

 nished to them. 



Crystals form within saturated 

 gases and chemical solutions and 

 magmas of various kinds, and are 

 usually so situated and surrounded 

 by material as to have etjual 

 chances of growing equally in all 

 except basal directions. But they 

 grow mainly, except possibly 

 during their first or microscopic 

 beginnings, in special directions only, thus furnishing 

 proof that certain parts of a growing cr\stal attract 



material to themselves in excess of others, and hence 

 have excessi\e attractive powers for the molecules of 

 matter of which they are constructed. These points 

 of major attraction, when occurring 

 upon the molecules of matter, are 

 called polos: and when occurring 

 upon crystals, axes. 



It is assumed that these attrac- 

 tive poles and axes are essentially 

 tiny fixed' charges of electricity, 

 and that their number and 

 arrangement is identical as re- 

 gards the molecules of a given 

 substance, but varies one sub- 

 stance or mineral with another, 

 and that the\' determine the form 

 and system to which crystals 

 belong, .\ccording to this theory, 

 the molecules of water, of which 

 snow crystals are constructed, 

 possess two major and opposite 

 poles, and six (or three) secondary 

 ones. Water, being a diamagnetic 

 substance, presumably tends to 

 arrange itself at right angles to 

 the two main and opposite poles 

 and axes, and hence defjosits itself 

 mainly upon and from the sec- 

 ondary poles and axes. Singularly 

 enough, though they grow largely 

 from these polar or axial parts, 

 there are oft-times moments when 

 (ortain crystals grow in equal or 

 i^reater degrees from other and 

 intermediate directions, as though 

 new axial points were established 

 upon them. It is assumed in such 

 cases that tiny additional electric 

 charges collect upon the crystals, 

 outside the main axial points, either directh' from 

 the indrawn molecules, or through overflow from 



