VITAL GROWTH AND CRYSTALLIZATION" 



39 



such conditions the third substance appears as visible crys- 

 tals possibly as a fine-grained crystalline powder. The 

 greater the amount of water added to the two solutions, the 

 larger are the crystals formed. 



If on the contrary the two solutions are more concen- 

 trated the crystals are smaller. No visible crystals appear 

 at all if the concentration of these two salt solutions is raised 

 to the highest possible level, that is, if more salt than water 

 is used to make up these salt solutions. The solid precip- 



Fig. 23. Rapid Settling Out of Insoluble Material by the Mixing of 

 Two Soluble Salts (a Sulfate and a Barium Salt) 



If these two salts are dissolved in a little water and mixed, the insoluble 

 product settles so rapidly that no crystals are formed; if they are mixed in a 

 more dilute solution, crystals are formed: the more dilute the solution, the 

 larger the crystals. 



itated substance then forms as a soft jelly-like mass. No 

 microscope is powerful enough to reveal the presence of 

 crystals in this soft mass, yet we may assume that invisible 

 small crystals are in it since crystals do form from more 

 dilute solutions. 



5. ARE CRYSTALS PRODUCED BY VITAL GROWTH? 



It is manifest, therefore, that the absence of visible crys- 

 tals in living organisms does not exclude the possibility of 



