S. Taker — Growth of Crystals. 



549 



slowly from the open end of the shorter tube, where it evapo- 

 rated. At first the solution ran down between the tube and 

 the beaker for a distance of 8 centimeters, forming on evapo- 

 ration a crust that in places attached the tube to the beaker. 

 Later, the flow became adjusted to the evaporation in such a 



' Fig. 5. 



Fig. 5. Diagram showing glass tube gradually being pushed back from 

 the side of the beaker by a growing mass of copper sulphate crystals. 



way that crystal growth continued only where the crust of 

 copper sulphate was in contact with the beaker near the top of 

 the tube. Gradually a hollow growth, shaped somewhat like a 

 stalactite, was formed between the end of the tube and the 

 beaker. As it increased in size the tube was pushed back 1*3 

 centimeters against the elastic resistance of the rubber tube 

 connecting the two glass tubes, and the mass that had formed 

 lower down between the tube and beaker was pulled apart, 

 leaving fragments adhering to both. Additions of material 

 seemed to take place only where the formation was in contact 



