320 



THE MICROSCOPE AND ITS REVELATIONS. 



solution; since on the temperature of the glass slide during the solidifica- 

 tion will depend the size and arrangement of the crystals. Thus Santo- 



G. 496. 



Radiating Crystallization of Santonine. 



nine, when crystallizing rapidly on a very hot plate, forms large crystals 

 radiating from centres without any undulations; when the heat is less 



FIG. 497. 



Radiating Crystallization of Sulphate of Copper and Magnesia. 



considerable, the crystals are smaller, and show concentric waves of very 



