Mr R. Adie on Electrical Experiments. 



303 



an explanation of tho apparent reduction of temperature, caused by 

 an electrical current passing through the cross, fig. 2, in the direc- 

 tion CAB. The bismuth bar is unequally heated (36), tho tem- 

 perature of tho positive, or entering end, being the highest, which 

 developes a thermo-electrical current, passing in the direction A C I, 

 or left to right ; but tho fluid in the cells of the battery, connected 

 with tho wires H and I, or the resistance in a powerful thermo elec- 

 trical scourco, prevent the current passing in that direction, it finds 

 less resistance to its passage through A E F, where the direction is 

 unchanged; and it acts on the galvanometer, as if a piece of ice had 

 been applied at A, while this joint is in reality slightly heated. Be- 

 fore leaving the consideration of M. Pelletier''s cross, I feel bound to 

 state, that should men of science attach any value to the whole of 

 tho series of experiments now placed before them, it was the action 

 of the electrical currents on this cross which first occasioned me to 

 commence these inquiries. 



40. The elevation of temperature, where an electrical current 

 passes from a good conductor, copper wire, mto an inferior one, lead, 

 supplies a ready mode of watching the action of a constant battery. 

 For this purpose, the bulb of a thermometer has to be placed upon 

 the joint, and wrapped round with a good non-conductor of heat; the 

 height the thermometer stands above the temperature of the room 

 indicates the activity of the battery. 



The annexed fig. 3, is a representation of this calorific galvano- 

 meter. A A, a thermometer. 



When the electricity, from a newly prepared Smee's battery of 

 48 superficial inches surface, was passed along a pair of antimony 

 and bisnmth bars, arranged as above, the thermometer A A rose 19° 

 above the temperature of the room. This amount of action is not 



VOL. XXXVII. NO. LXXIV. OCTOBER 1844. U 



