Improvements in Science. 447 



fnto the stomach of a torpedo killed it in ten minutes ; its 

 death is accompanied with stronger shocks than usual, 

 and with convulsions. When the torpedo has ceased to 

 give electrical shocks, even when irritated, if we lay bare the 

 brain, and touch gently the posterior lobe of the brain which 

 gives nerves to the electrical organ, stronger shocks than 

 usual (3 or 4) are produced, but having the same direction 

 from the back to the belly. If, in place of simply touching 

 the surface of the brain, it is wounded without taking the 

 same precaution, then very strong shocks are renewed, 

 but without having the same constancy in the direction of 

 the current. These facts, and especially the latter, are 

 sufficient to shew, Matteucci thinks, that the electricity of 

 the torpedo is not produced in the organs situated on each 

 side of the animal ; that the current receives its direction 

 from the brain, and that in the electrical apparatus, the 

 electricity is only condensed as in the Leyden jar. 



Developeinent of Electricity. — M. De La Rive has pub- 

 lished some very elaborate memoirs, in which the question 

 is discussed at great length. How is voltaic electricity 

 developed ? He has drawn the following conclusions : — 

 1. That in his memoirs he has endeavoured to corroborate 

 by new facts the deductions which he had formerly drawn 

 relative to the necessity of a chemical action for the pro- 

 duction of voltaic electricity, and the impossibility of 

 developing electricity by simple contact. 2. The attention 

 which he has paid to the effects of current, and the dyna- 

 mical effects have led him to observe, that the quantity of 

 electricity accumulated at the poles under the form of 

 tension is greater in proportion as the two electrical prin- 

 ciples have less facility in uniting through the pile itself, 

 and as the pile contains a greater number of pairs. In 

 the same manner, it is necessary for the dynamical effects, 

 that the pile be little of a conductor, and contain, conse- 

 quently, a sufficient number of pairs, in order that the two 

 electrical principles may re-unite in greater proportion, by 

 the medium of conductors placed between the poles than 

 through the pile itself. 3. Having found that the quantity 

 of free electricity disengaged in a given time from each pair 

 of plates exercises no sensible influence on the tension of the 

 poles of a pile, since this kind of effect is not instantaneous. 



