CANCER 



139 



^aj/f^c/7 e/nef neet/Ze 



/?oj/y/o/>t2^/!a: neec/fe 



a. Hard, dry formation yielding a low galvanometric deflection ; 

 h,h. Soft, wet, apparently putrescent area. 



From the shoots I obtained deflections of 20 and 30mm., 

 as compared with 2,000 or 3,000 from those of a healthy- 

 potato. Deflections taken from 6, &, to a, varied from a 

 few millimetres to off scale, and here and there I obtained 

 reversals, showing that the tuber was not everywhere 

 electrically dead. For the most part, however, the sign 

 remained unchanged. 



As a further experiment I selected a sound potato with 

 shoots from two eyes : 



/^^J- 



It was perforated or pricked at a, as before, but this time 

 I used a cell of 1.5 volts only. Perforation extended to 

 a depth of f-inch, and the negative needle was afterwards 

 inserted to a depth of |-inch ; positive needle to |-inch. 



I. 



