process of filtration and affect or destroy it, and this factor 

 can be found only in the protoplasm, the vital element of 

 the cells; for we know that the sublimate acts with psr- 

 nicious effect on it and in such a manner that it destroys its 

 entire power of reaction; it kills it, as we say. 



The experiment under discussion has, therefore, great 

 significance for our view of the vital processes in the plant ; 

 it proves beyond doubt that these processes are in no way 

 of a purely mechanical nature, but that there is something 

 underlying all this, a hitherto inexplicable something, which 

 we call "life." In all vital activities, physical and chem- 

 ical processes certainly do occur; they do not, however, 

 take place spontaneously but are made use of by the vital 

 element of the plant to produce an effect that is desirable 

 or necessary for the vital activity of the plant. If the vital 

 element is dead, no matter how favorable the conditions 

 may be for chemical and physical processes, these do not 

 take place and the effect necessary for life is not obtained. 

 It is very remarkable after all that according to the ex- 

 periment of Haberlandt this peculiar relation should be- 

 come apparent in a process that is so open to our investi- 

 gation as the filtration of water through the cell-wall of a 

 plant. • 



After what has been said I consider this simple experi- 

 ment of Haberlandt of great significance ; for it is a direct 

 proof of the existence of a vital force. One may resist to 

 kis heart's content, but without avail; vital force is again 

 finding its way into science. More and more cognizance 



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