536 



S. Taker — Growth of Crystals. 



after a number of volunteer crystals had begun to develop in 

 the crystallizing dish. 



The foregoing experiments prove that under certain condi- 

 tions the growth of crystals may be accompanied by the devel- 

 opment of a linear force, and that the failure of some 

 investigators to find evidence of this force is due to the condi- 

 tions under which their experiments were conducted. The 

 writer has formulated an hypothesis to explain the growth of 

 crystals in directions in which mechanical hindrances oppose 



Fig. 1. 



Saturated Copper Sulphate Solution 



Cold Water 



Fig. 1. Apparatus for growing crystals under pressure in a solution of 

 approximately constant temperature. 



growth, but since this problem is intimately related to the ori- 

 gin of the terraced cavities, it is necessary to consider both 

 problems at the same time. 



In all of the experiments described above, whenever a meas- 

 urable lifting of a weight by a growing crystal took place, the 

 crystal at the close of the experiment had a terraced cavity or 

 hollow on its under side, and this was the case even when a 

 crystal was used that had only plane faces in the beginning. 

 In a very few instances indistinct shallow hollows seemed to be 

 present also on the upper surface of covered crystals, but none 

 had a depth of so much as 0*1 millimeter. Moreover, careful 

 measurements show that the distances through which weights 



