FUNCTION IN PLANT LIFE 19 



reduced this deflection, and it was necessary to give a 

 further five minutes' charge. At the end of this time it 

 went rapidly off-scale positive and remained off-scale for 

 fifteen minutes. The connections were then earthed for 

 five minutes through 5,000 ohms, when the charge was 

 found to be dissipated and the true polarity restored. 



In a second experiment with the same onion a further 

 ten minutes' charge was not fully discharged until forty 

 minutes after the first reading. 



A STICK OF RHUBARB. 



This was charged for five minutes and the cell dis- 

 connected. The deflection was then off-scale positive. 

 Five minutes later it had fallen to 160 mm. positive, and 

 at the end of the tenth minute risen to 180 mm. As this 

 might have been due to the effect of the juice upon the 

 electrodes, these were removed, cleaned, and carefully 

 reinserted, when D = 180 mm. positive, rising in a further 

 five minutes to 250 mm. Five minutes E, however, 

 removed the charge and the original polarity returned. 



THE APPLE. 



This fruit was large, ripe, and in perfect condition, and 

 exhibited an unusual quantity of current. Ten minutes' 

 charge with 1-5 volts merely reduced the deflection to 

 50 mm. negative. I therefore gave it another five 

 minutes, when D = rapidly off-scale positive. Ten 

 minutes later it being still off-scale the connections 

 were put to E for five minutes and the electrodes removed 

 and cleaned. D was then 250 mm. positive and five 

 minutes later 235 mm. positive. It had then, unfortu- 

 nately, to be left insulated until the next day, when it 

 had fully recovered. 



