SALT AND WATER IN LIFE AND GROWTH 



127 



ferrocyanide). A surprising development sets in within a 

 few minutes. A plant-like structure develops from the 

 piece of yellow prussiate. It remotely resembles a cactus, 

 showing fine branches and twig-like ramifications (Fig. 37). 



Fig. 37. Artificial Plant-like Structure Growing from Yellow 

 Prussiate of Potash in a Dilute Copper Sulfate Solution 



The process which leads to the formation of this structure 

 is diagrammatically explained in Figure 38, diagrams 1 to 4- 

 We see how the piece of yellow prussiate dissolves, forming 

 a solution around itself. Observe the second diagram. It 

 interacts at once with the copper sulfate of the solution in 

 the test tube, forming a new material of brown color, chem- 

 ically known as copper ferrocyanide, which is insoluble and 



