176 Intellwence and Miscellaneous Articles, 



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lar contraction in the latter. He laid the sciatic nerve of one leg of 

 a prepared frog on the thigh of another, and by touching the nerve 

 of the latter with an arc of zinc and copper this was convulsed, and 

 at the same time the first leg, the nerve of which formed no part of 

 the voltaic circuit, was simultaneously convulsed, the legs all moving 

 as though they formed part of the same animal. 



4th. M. Matteucci explained some joint researches of himself and 

 M. Longet, by which it was proved that a diiFerent galvanic result 

 is produced upon the nerves of an animal at a certain period after 

 death, if the current acts upon the nerve of motion, or centrifugal 

 nerve only, from that Avhich ensues if the mixed nerve, centrifugal 

 and centripetal, be subjected to the current ; in the former case the 

 muscular contraction takes place at the interruption of the direct cur- 

 rent, or that which passes from the nervous centre to the extremities, 

 and the commencement of the inverse current, or that which passes 

 in the opposite direction ; while in the latter case the reverse effect 

 obtains, the contraction taking place at the commencement of the 

 direct and at the interruption of the inverse current. 



M. Matteucci also communicated to the Chemical Section the re- 

 sults of some experiments made by him with the view of establishing 

 the relation which the amount of mechanical work realized by the 

 consumption of a given quantity of zinc acting as a voltaic combina- 

 tion upon the limbs of a frog, bears to the amount of work realized 

 by the same quantity of zinc employed as a generator of mechanical 

 force in other inorganic applications. A given weight is attached to 

 the feet of a recently-prepared frog, this and the weight are suspended 

 from a platina wire by a portion of the spine, and another platina 

 wire passes through the lower part of the sciatic nerves, these wires 

 are connected with the terminals of a voltaic battery, a voltameter 

 being interposed in the circuit. 



By making and breaking voltaic contact, the muscles contract, and 

 the weight is raised. 



By connecting a contact breaker with the moving limbs, these are 

 enabled to interrupt and complete the voltaic circuit by their own 

 contractions, and a register attached shows the number of interrup- 

 tions in a given time. 



An index is also attached to the weight, which bearing upon a re- 

 volving sooted disc, registers the distance and velocity of the motion 

 of the weight. Thus we get the elements of time, space, and weight. 

 From experiments performed in this manner M. Matteucci finds that 

 3 milligrammes of zinc consumed in twenty-four hours gives .5 '54 19 

 kilogrammes of weight raised through a given space, while the same 

 quantity of zinc, or its equivalent of carbon, employed to generate 

 motion by combination in a steam-engine gives 0'''834 ; or employed 

 to work an electro-magnetic machine, gives O'^'SS. 



Several reductions must be made to eliminate extraneous actions 

 which do not contribute to the resulting effect ; thus a voltaic bat- 

 tery of sufficient intensity to decompose water must be much more 

 powerful than is requisite to convulse the limbs of the frog. The 



