198 C. H. Matteucci*s Researches relative to the Torpedo^ 



of half a millimetre. By slightly moving the upper metallic 

 plate the animal became irritated, and at the same moment 

 the two leaves approached one another and the report of the 

 spark was instantly heard. 



Matteucci has carefully studied the internal and external 

 causes which influence the discharge of the torpedo ; among 

 the external causes we may distinguish, besides the mechani- 

 cal excitement, heat, in water at 18° Reau. The torpedo 

 seldom lives more than five or six hours, preserving all its 

 electrical power ; on diminishing the temperature this power 

 instantly ceases. On heating the water the discharges begin 

 afresh, but if the temperature is increased to + 30° Reau., 

 as we ourselves also observed, the animal after several dis- 

 charges suffers violent contractions and dies in a sort of te- 

 tanic state. 



Matteucci having analysed the air contained in sea-water, 

 has determined the variations which result from this with re- 

 spect to the respiration of the torpedo. According to the ob- 

 servations which he has made relative to this point, when the 

 torpedo is tormented it respires more than that which is not ; 

 and what is most singular, if the fact be true, is that the for- 

 mer produces under the same circumstances less carbonic acid 

 than the other : it would seem in general that the intensity of 

 the electric function is in proportion to the force of the circu- 

 lation and of the respiration. 



The action of the most energetic poisons produce the fol- 

 lowing effects : — Hydro-chlorate of strychnia introduced into 

 the mouth and stomach of a torpedo produced almost imme- 

 diately violent contractions in the vertebral column accompa- 

 nied with powerful discharges, afterwards of weaker discharges, 

 and the animal expires in violent convulsions. Hydro-chlorate 

 of morphine produces in eight or ten minutes after its intro- 

 duction into the animal very powerful discharges; it some- 

 times gives more than sixty discharges in ten minutes. 



The current of an electrical apparatus composed of eight 

 pairs directed from the mouth to the branchiae, and to the epider- 

 mis of the interior of the organ, produces strong discharges. 

 Electricity acts in this case probably only as a violent excitative. 

 Matteucci having cut the half of the organ either in a hori- 

 zontal or in a vertical direction, and having placed between 

 the divided parts a plate of glass, the discharge still took place; 

 this was the case also even when the organ held to the ani- 

 mal only by a nervous fibre : the effects did not cease before 

 the substance of the organ became coagulated by the action 

 of the acids or of the boiling water. We may remark with 

 respect to this, that several philosophers, and especially Gal- 



