1923] SEIFRIZ— SALTS 



393 



"oligodynamic" water. The term " oligodynamic " is Nageli's 

 (2), and refers to water which has a very slight trace of copper. 

 The slight trace of copper in water distilled in a copper still, or 

 water in which copper coins have remained for a day or two, causes 

 a very pronounced reduction in osmotic value of Elodea cells which 

 are allowed to remain in the oligodynamic water over night. If an 

 untreated leaf and a leaf which has been in the copper water for 

 eighteen hours are plasmolyzed with 0.35 M KN0 3 , within less than 

 a minute all of the cells of the treated leaf (with the exception of the 

 few which have been killed) will be slightly plasmolyzed, while none 

 in the control leaf is plasmolyzed. 



Stimulation to protoplasmic streaming.— Little streaming 

 is to be observed in cells treated for a short time in potassium nitrate, 

 sodium chloride, or calcium chloride. After prolonged treatment 

 in these salts no streaming at all is seen. In strontium chloride, 

 barium chloride, and oligodynamic water the stimulation to stream- 

 ing is very great. Eighteen hours in a 0.064 M SrCL solution is 

 sufficient to arouse many cells to active streaming in a leaf reason- 

 ably sensitive to strontium. Two days will cause a great abundance 

 of streaming, much of which is abnormal. In a leaf which had 

 been in 0.128 M SrCl 2 for seventy-two hours (many cells succumb 

 to so high a percentage of strontium for so long a period of treat- 

 ment), the individual paths of flow in some cells were so numerous 

 and so indefinite in their direction that all the chloroplasts seemed 

 to wander about aimlessly. A very pronounced increase in the 

 thickness of the protoplasmic layer, equaling five times that of the 

 normal cell, resulted from treatment in strontium. The increase 

 in thickness of the protoplasmic layer is probably the result of 

 increased permeability of the protoplast as a whole to water and a 

 resulting excessive imbibition. It is interesting to note that this 

 highly swollen protoplast, undoubtedly in the gel state, continues 

 very active streaming. Copper also has a very pronounced stimu- 

 lating effect on protoplasmic streaming, even more so than strontium 

 and barium. 2 



2 A full discussion of the stimulation to streaming caused by strontium, barium . 

 copper, alcohol, and saponin is given in a recently published article (7). 



