chap, i Processes of Absorption of Water 275 



causing the absorption of poisons. He thus killed con- 

 siderable lengths of the structure, in many cases 10-12 

 metres. He found that nevertheless water continued to 

 pass up the stems, often to a distance of several metres 

 beyond the injured region. 



It is difficult after these experiments to see how the cause 

 of the rise can be dependent on living elements. Stras- 

 burger suggested a return to the view that the phenomenon 

 is purely physical, but he admitted that none of the explana- 

 tions based up to 1891 on such a hypothesis account satis- 

 factorily for the facts. 



The advocates of the living-cells hypothesis replied with 

 considerable energy to Strasburger's objections, criticizing 

 his experiments and the conclusions he based upon them. 

 The most prominent was Schwendener, whose work appeared 

 in 1893. He said that though a continuous column of 

 water cannot be raised by atmospheric pressure to a greater 

 height than the barometric column, this is not the case 

 with a Jamin's chain. He also called into question the 

 statement that in Strasburger's experiments the cells were 

 undoubtedly killed. 



It is impossible in the present work to enter fully into 

 the details of the controversy, which was maintained with 

 some vehemence for a considerable time. From the work 

 of Strasburger, however, we may trace new investigations 

 of a physical character which had great weight, and which 

 led the controversy to the position it occupied at the close 

 of the century. 



These investigations are based upon a property that 

 water has been shown to possess of resisting tensile stress, 

 so that the columns of liquid may be lifted bodily up the 

 narrow tubes in which they are found. The theory that 

 such is the method by which the water passes up the stem 

 dates from 1894 and 1895, and was advanced separately by 

 Dixon and Joly in Ireland, and by Askenasy in Germany. 



s 2 



