66 



Physico-Chemical Properties of Vegetahle Saps [March, 



B. Specific electrical conductivity. (Data, Tables 7-1 1.) 

 The electrical conductance of plant saps is in a large measure due 

 to the presence of inorganic salts. Organic acids probably play a 

 very minor röle because of their low ionization constants, 



The mean values and the probable errors of mean values for 

 the conductivities of the saps of the two parts of the proliferous 

 fruit are, for the three series in which the number of determina- 

 tions are numerous enough to make it worth while to calculate 

 probable errors, given in the appended summary: 



Confining our attention for the moment to the mean values, we note 

 (a) that they are of about the order of o.i N KCl; and {h) that 

 they differ significantly from series to series. Thus, the difference 

 between Series C and Series D is, for the wall, 0.003013 + 

 0.000224; for the prolification, 0.001053 + 0-000332. The differ- 

 ence between Culture D and Culture E is, for the wall, 0.00 1 162 

 + 0.000217; for the proHfication, 0.001440 + 0.000181. These 

 differences are several times as large as their probable errors. 



The ränge of Variation in observed conductance from sample 

 to sample is indicated below: 



Experiment Wall 



A 0.013350 — 0.013404 = 0.000054 



B O.Ol 1592 — 0.015692 = 0.004100 



C 0.014347 — 0.016379 = 0.002032 



D 0.010400 — 0.014233 = 0.003833 



E O.Ol 1602 — 0.014803 = 0.003201 



Prolification 

 0.008950 — 0.010025 = 0.001075 

 0.008631 — O.OIO69I = 0.002060 

 0.009153 — 0.015054 = 0.005901 

 0.007393 — 0.009501 = 0.002108 

 0.008063 — 001 1499 = 0.003436 



Expressing the results in terms of the Standard deviation we find : 



Experiment 



c 



D 



E 



Wall 

 0.000610 + 0.000073 

 0.001026 + O.OOOI4I 

 0.000884 ± 0.000094 



Prolification 

 0.001305 + 0.000156 

 0.000599 + 0.000082 

 0.000931 + 0.000099 



