16 



HATCH EXPERIMENT STATION. 



[Jan, 



Experiments with Radishes. 



Table I. — Shon-ing the Effect of Current Electricity upon the Growth 

 of Radishes (^Baphnnns safivus h.). Nor7nal Plants taken as the 

 Standard at 100. 



[Duration of experiment, 38 daj's.] 



1 Loss. 



Per Cent. 

 Total average weight, in grams:— Normal. Treated, gained. 



Of roots, 4.83 5.12 6.00 



Of tops 10.35 11.02 4.45 



Of whole plant 15.38 16.14 4.93 



In Table I., in which six experiments are shown, three 

 normal and three treated, the results are not in every way 

 satisfactory. The current strengths were determined only 

 once or twice in each instance, and these were estimated by 

 means of the electro-motive force of the cell and resistance 

 of the soil, and also l)y a milammeter. The current strengths 

 given, therefore, represent only those which were found at 

 the time of the measurements ; and, since the resistance of 

 soil is constantly changing with the movements of the water 

 currents and with the ever-changing moisture conditions, 

 due to waterino-, the figures ofivino^ strenoths of current must 

 not be considered as averages. The strengths of current 

 employed in the experiments shown in the first five tables 

 vary, probably from .05 to 1 milliampere. 



In the interru})ted induced current experiments the cur- 

 rent had a duration of only about ten seconds per hour. 

 This was accom[)lished with a clock arrangement and with a 

 Du Bois-Reymond induction apparatus. It should be pointed 

 out, however, that with the use of this apparatus only ap- 



