235 



work. The number of sparks in a minute was now greater, 

 which proves that Ihe conducting power belween the point 

 and the water in the glass-vessel had been augmented. 

 The water was now transported from the meniscus 

 up into the tube and formed one or more dröps, but it 

 happened only when the point was conneeted with the ne- 

 gative pole in the machine. 



As tiiis remarkable fact had been confirmed, we pro- 

 ceeded to an investigation of the machine, when one of its 

 poies was in connexion with the earth. The situation of 

 the poles was determined by the light-phenomenon on the 

 combs. As from the points of the comb there went out red- 

 dish-violet streams of light against the rotahng cylinders, 

 the corresponding pole was negative; when again bright 

 points appeared, it w^as positive. 



When the point s was connectid with the positive pole, 

 a httle dröp could be seen, but it was not caused by the 

 rising water, but on the contrary by the descending. The 

 descending water stream was caused by the positive cur- 



