VITAL GROWTH AND CRYSTALLIZATION 17 



of any plant or animal. Moreover, the crystal looks the 

 same all the way through, as is evident when it is cross- 

 sectioned. Such uniformity is never found in any living 

 thing. 



However, by a slight modification of the conditions of any 

 crystallization we can see that a general similarity to life 

 appears. We add gelatin, or starch, or another similar 

 slimy material to a salt or sugar solution from which crystals 



Fig. 5. Leaf-like Forms Produced by Crystallization of Ordinary 

 Table Salt in a Medium Containing Gelatin 



If ordinary table salt crystallizes from a water solution to which gelatin 

 is added, the small crystals formed join to build up an aggregate which 

 resembles a leaf; this is a striking example which shows that crystallization 

 can produce life-like forms under certain conditions. Natural size. 



are growing. With such an addition, there is no longer a 

 growth of one, or of a few large crystals, but the crystal 

 now breaks up into countless small ones which group them- 

 selves in such a manner that the entire aggregate presents 

 the outline of a leaf (Fig. 5). Similar aggregates of crys- 

 stals are formed which resemble trees or plants with twigs 

 and branches. We see, therefore, that under proper con- 

 ditions crystallization may lead to life-like forms, a fact 



