Galvanic E.vperttnenis. 41 



out any intervention of the pile, and without any armature 

 applied to the heart. It is very remarkable, that when the 

 former is touched firft, and then the arming and fpinal mar- 

 row, the contradions of the heart which fellow are more in- 

 Hantaneous, and (ironc;er, than when the arming of the fpinal 

 marrow is lirll touched, and then the heart. In a memoir 

 on Galvanifnj, read in the la(l public fitting of the academv,. 

 I gave an account of a great number of experiments, made 

 efpecially on frogs, which exhibited a fimjlar phaenomenon. 

 In thefe animals I obferved, a great number of times, that, 

 when the arming of the crural nerves was touched firit, and 

 then the mufcles of the thigh, there were no contractions, 

 or the contraftions were exceedingly weak ; and, on the other 

 hand, that when the mufcles of the thighs were firft touched, 

 atid then the arming of the crural nerves, as long as the leaft 

 vitality remained in the organs the contraftions of the muf- 

 cles were coitftant and violent. In the memoir already men- 

 tioned I have endeavoured to account for this phsenomenon, 

 to which I {hall recur when, by. a great number of trials, we 

 fhall have afcertained that it is as general in men as I found 

 it in frogs and other cold-blooded animals. 



The fecond manner in which we tried the influeflce of 

 Galvanifm on the heart was by arming the ncrvi vagi and 

 the large fympathetic. The objeft of thofe experiments will 

 be readily comprehended by anatomifts acquainted with thtf 

 details of neurology. In thefe, as well as in the fird and' 

 other experiments where we armed the cardiac nerves them- 

 felves, we obtained contra6lions in the heart. In this, as in 

 the former cafe, the contractions obtained when the heart 

 was firft touched, and then the arming of the nerves, were 

 much ftrongcr than when the arming of the nerves was 

 touched firlt, and then the heart. In this method we evcii 

 obferved that the Galvanic experiments fomeiimcs failed. 



The third kind of experiments on the heart were performed 

 by means of the pile. The pile we employed on the lotil 

 ofAugult, for the experiments on the firft decapitiited cri- 

 minal, was coiiipofed of fifty plates of filver and as many of 

 zinc, with pafieboard moiltcncd with a Itrong folution of 

 muriate of foda. The filver was mixed with a tenth part of 

 copper. This is the proportion which we found molt favour- 

 able to the intenfity of the figns of Galvanifm : 



Metre. 



The diameter of the filver plates was - 0-036 

 Their thicknefs - - - 0'00I5 



■f be dimenficns of the pieces of pafteboard were the fame. 



']'he 



