Mason — Electrolytes in the Leaf-sap of Syringa vulgaris. 655 



The depressions recorded under A e in Table I, so far as affected by these 

 considerations, are too low, and that of the non-electrolytes correspondingly 

 high. It is clearly impossible to apply a correction for these factors without 

 a knowledge of the nature and concentrations of the sap ions. The error 

 thus introduced into work of a comparative nature on the leaf-sap of a single 

 species is not, it is believed, of the first importance. The results obtained by 

 the adoption of this method of discriminating between the part played by 

 electrolytes and non-electrolytes are, however, necessarily of a preliminary 

 nature. 



The Application of the Viscosity Correction to the Conductivity of the Leaf -Sap 



of Syringa vulgaris. 



In Table III are recorded the results of some experiments which were 

 carried out on Syringa vulgaris in order to determine the validity of the 

 application of the linear viscosity correction to the conductivity of the sap of 

 this plant. The material for the first five experiments was gathered from 

 trees growing in the grounds, and the last two in the Botanical Gardens of 

 Trinity College, Dublin. 



Table III. 



Syringa vulgaris, June-July, 1919. 



As in Aucuba japonica (Table I), the concentration of electrolytes [A ] 

 tends to diminish with a rise in the non-electrolyte content [A - Aj. It 

 will be seen also that the sap extracted from leaves from the Botanical 

 Gardens has somewhat higher viscosity and non-electrolyte content, and a 

 smaller concentration of electrolytes than that, from the grounds of the 

 College. 



A tendency to over-correction is shown by the figures recorded_in the 



iV 

 C KCl column. [Conductivity of yjr aqueous KCl = - 00/15j. 



