VITAL GROWTH AND CRYSTALLIZATION 



L9 



c d 



Fig. 6. Photographs of Plates with Crystallizing Copper Chloride 



ACCORDING TO PfEIFFEr's METHOD 



(§ natural size) 



(a) Copper chloride without addition. 



(6) Copper chloride crystallizing with addition of one drop of an extract 

 of a water-lily flower to 1 cc. of the 25 per cent copper salt before crys- 

 tallization. 



(c) Same with the addition of one drop of extract from an agava. 



(d) Same with the addition of one drop of extract from a camomile 

 flower. 



All the pictures reveal the striking formative influence of the addition of 

 plant juices to the otherwise shapeless crystalling salt. Note particu- 

 larly the appearance of thorn-like crystalline needles after the addition of 

 the agava juice. 



