116 Experimental Philosophy. [Ilecture 9. 



wire instead of a string, which, he observes, may 

 be coiled upon a strong rod or bar of solid glass, 

 held in both hands. Sparks may, in this manner, 

 be taken from the wire or string, as from a com- 

 mon electrical machine. For security, however, 

 a key must be suspended by a wire from that 

 which is coiled up, so as to touch a half-crown, or 

 a plate of metal lying on the ground. If the key 

 is then lifted a little from the plate, a stream of 

 fire will be seen proceeding from the key to the 

 plate; but if a sensation like a cobweb on the 

 face takes place, it will be prudent to throw down 

 the glass bar, and leave the kite to itself*. Elec- 

 tricity may be again attracted from the atmo- 

 sphere, if a long wire screwed into the knob of a 

 Leyden bottle, and pointed at the extremity, is 

 held aloft in the air ; and if this experiment is 

 made in the night-time, when thunder and light- 

 ning are near, a star will appear at the point of 

 the wire, and if the bottle is touched with the 

 other hand, a shock will be received. A man also 

 standing upon a glass stool, and holding in his 

 hand a fishing-rod coated with tin-foil, or any 

 long metal instrument, aloft in the air., will gene- 

 rally be more or less charged with electricity, in 

 proportion to the state of the atmosphere, and 



* Professor Richmann, of Prtersbnrgh, in consequence 

 of disregarding the due precautions, was killed while he 

 was conducting the experiment of drawing electricity from 

 a thunder cloud. 



