COHESION AND CRYSTALLIZATION 



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drops. The particles of Indian ink may be seen passing from 

 one drop to another, the coloured circles become elongated 

 towards one another, touch, and finally unite. If, as in Fig. 23, 



FlG. 22. — The same drops after 30 minutes. The granulations have 

 agglomerated at the centre of the drops. 



the drops are of different size, the larger one will have a 

 preponderating attractive action and eat up the smaller drops. 

 In the figure, six small drops are placed around a large one, 

 and the smaller drops have begun to be 

 deformed and to move towards the larger 

 drop. This central drop is also deformed, 

 and has assumed a more or less hexagonal 

 form, under the influence of the attraction 

 of the six smaller ones. It may be noticed 

 that the least prominent angle of the hexa- 

 gon is opposite the small drop which is 

 farthest away from it. whilst one of the 

 smaller drops has already begun to be 

 swallowed up by the large one. This 

 cohesion phenomenon is very slow in its action, but after 

 an hour or two the central drop will be found to have com- 



Fic. 23. — Attraction 

 between coloured 

 drops in an isotonic 

 solution. 



