MATTER AND FORCE 71 



If I could show you the actual progress of this mo- 

 lecular architecture, its beauty would delight and astonish 

 you. A reversal of the process of crystallization may be 

 actually shown. The molecules of a piece of ice may 

 be taken asunder before your eyes; and from the man- 

 ner in which they separate, you may to some extent 

 infer the manner in which they go together. When a 

 beam is sent from our electric lamp through a plate of 

 glass, a portion of the beam is intercepted, and the glass 

 is warmed by the portion thus retained within it. When 

 the beam is sent through a plate of ice, a portion of the 

 beam is also absorbed; but instead of warming the ice, 

 the intercepted heat melts it internally. It is to the 

 delicate silent action of this beam within the ice that I 

 now wish to direct your attention. Upon the screen is 

 thrown a magnified image of the slab of ice: the light 

 of the beam passes freely through the ice without melt- 

 ing it, and enables us to form the image; but the heat 

 is in great part intercepted, and that heat now applies 

 itself to the work of internal liquefaction. Selecting cer- 

 tain points for attack, round about those points the beam 

 works silently, undoing the crystalline architecture, and 

 reducing to the freedom of liquidity molecules which had 

 been previously locked in a solid embrace. The liquefied 

 spaces are rendered visible by strong illumination. Ob- 

 serve those six-petalled flowers breaking out over the white 

 surface, and expanding in size as the action of the beam 

 continues. These flowers are liquefied ice. Under the 

 action of the heat the molecules of the crystals fall asun- 

 der, so as to leave behind them these exquisite forms. 

 We have here a process of demolition which clearly re- 

 veals the reverse process of construction. In this fashion^ 



