1902] 



ELECTRICAL CONDUCTIVITY OF PLANT JUICES 



91 



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 1 



i 



t 



7. PORTULACA AND AmARANTUS. 



Conductivity measurements were made for two more species, 



and 



the results will be given together. In each 



case roots, 



stems, and leaves were used with the followinof results ; 



1 



i 



1 

 1 

 1 



1 



Portulaca oleracea 

 Sp. cond. of juice 



Ainarantiis 



retroflexus. Sp. cond, 



of juice. 



1 



0.02445 

 0.02154 

 0.01069 



O.OI7II 

 O.OI519 

 0.01328 









These figures show that for both species there is a progres- 

 sive increase in the specific conductivity from the roots upward. 

 No ash determinations were made for either of these species. 



The results obtained and recorded in the foregoing pages 

 indicate that a method may be afforded of determining the 

 relative amounts of ash in different parts of the same plant. 

 Conductivity determinations of the juice from the same species 

 grown on different kinds of soil would probably yield interesting 

 results. It is known that the ash of any given species varies in 



it oug^ht to be 



amount throughout the 



period of growth, and 



possible to determine the extent of the variations by means of 

 conductivity measurements. If this is possible, then the much 

 more laborious process of an ash determination would not be 

 necessary. 



It may be noted in this connection that there is a difference 

 of potential between the shoot and root of a plant, the root being 

 electro-negative and the shoot in a state of positive electrifica- 



tion. 



Whether the greater conductivity of the cell sap in the 



shoot is in any way connected with this condition remains an 

 open question. The facts at least are suggestive. 



CONXLUSIOXS. 



A number of conclusions can be drawn from the foregoing 

 records of conductivity determinations. Although others are 

 indicated, a greater number of species must be examined before 



