II 



ASCENT OF SAP IN STEMS 



45 



above than in the lower parts of the tree. The record 

 of a few measurements will illustrate this. Under A in 

 Table 3 is given the depression of the freezing-point, which 

 is proportional to the concentration of the total dissolved 

 contents of the sap ; while under C is recorded the con- 

 ductivities expressed as reciprocals of the resistances 

 measured in ohms. These give a measure of the content of 

 electrolytes. 



Table 3. 

 Showing the concentrations of Wood-sap in Stems and Roots. 



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Id., "Les causes de l'ascension de la seve," Ann. des Sciences Nat. Bot., 

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