1891.] 31 [Bachc. 



illustrating a law which should have been expected to hold good 

 whatever figure and volume the lines of force between the poles 

 might assume and occupy. The experiments clearly proved, too, 

 that the resistance of water is very much greater than that of 

 an infusion not seemingly dense. 



There seems to be with some persons a belief that water is a 

 good conductor, because current electricity so readily discharges 

 itself by means of moistened surfaces. But current electricity 

 so discharges itself through a film of water covering non-con- 

 ducting surfaces in default of any other conductor whatever ; 

 and static electricity, for the same reason, readily vanishes through 

 aqueous vapor, because of the fact that the vapor impairs the re- 

 sistance of dry air as a dielectric. Yet electricity, in these two 

 manifestations, acts thus, of course, not from choice but from 

 necessity, taking, however imperfect, a path of conduction when 

 there is no other, and the better of two paths when they differ. 

 in proportion to their relative conductivity. Other persons 

 imagine that water is a worse conductor than it really is. Any 

 one who uses a hydro-rheostat well knows the highly resistant 

 property of water to the electric current ; but as free and in 

 large volume it is not practically so resistant as it is sometimes 

 thought to be, as any one may prove for himself by the rude ex- 

 periment of plunging in an ample basin of water the sponge of 

 one reophore of a medical galvanic battery, yielding from thirty 

 to forty volts, while the sponge of the other reophore is placed 

 on the back of the hand submerged in the water at the distance 

 of four or five inches. The hand, the most callous part of the 

 body except the heel, feels the current distinctly in every part, 

 and if it has but the smallest abrasions of the skin in places re- 

 mote from each other, the electric current makes them sting, 

 finally condensing strongly at the pole on the hand. 



After trying the experiments described, I flashed one hundred 

 and ten volts through a glass tube, with half of a cubic centi- 

 meter of hay -infusion containing protozoa, with the poles half an 

 inch apart ; and also flashed one hundred and ten volts through 

 a looped wire going from top to bottom of a small bottle con- 

 taining four centimeters of the infusion. In neither case could 

 subsequent microscopical examination detect that the organisms 

 had been affected in the least. The whole of the current, of 

 course, passed through the organisms in the tube. In the case 



