VITAL GROWTH AND CYSTRALLIZATION 21 



thorns ; again with extract of a camomile flower, a delicately 

 ramified pattern of great regularity and beauty appears 

 (Fig. 6). 



Even more striking variations appear if extracts from 

 healthy and diseased plants are added to the crystallizing 

 salt. PfeifTer took seeds of a healthy straight pine tree and 

 seeds from another pine tree which grew crooked. Both 

 kinds of seeds were crushed in a mortar, water was added, 

 and the extract thus prepared was separated from the seed 

 fragments. A few drops of the two extracts were added to 

 crystallizing copper salt. Where the extract from healthy 

 seeds was added, a crystalline picture with perfectly straight 

 or gently curved lines developed, and all these lines radiated 

 from a common center in perfect harmony (Fig. 7a). The 

 extract from the crooked tree's seeds, on the contrary, pro- 

 duced an irregular picture. The lines do not radiate from a 

 center, but seem to converge to several points which are 

 irregularly distributed (Fig. 7b). 



These experiments demonstrate the presence of myster- 

 ious form-producing forces, or properties, in the living sub- 

 stance. And these forces manifest themselves not only in 

 the living plant, but can also be put to work in a crystal- 

 lizing salt. 



Next, PfeifTer investigated the forms produced in crys- 

 tallizing salts by the addition of traces of human blood to 

 see whether it was possible by this method to find differ- 

 ences between the blood of healthy and sick persons. From 

 1930 to 1935 he performed more than 30,000 crystallization 

 experiments which show that there is a difference. 



He took two or three drops of fresh blood, mixed it with 

 about five times as much water, and added two drops of this 

 diluted blood to a third of an ounce of salt solution. This 

 mixture was poured on a flat round dish, about three inches 

 in diameter, where it slowly evaporated. For a control, 

 the same solution, but without any addition, was allowed to 



