l66 Volta on Ari'imal TJctfricttv, 



moft careful attention and a certain dexterity are require^ 

 in order to enfure fuccefs to the experiment, which I have 

 often performed to the great afionifhment of the fpeAators, 

 and which any one may repeat as was done by my fiicnd 

 Ilumboldt. That philofopher has ahxady pubHlhed fome of 

 the moft Itriking and decifivc of thefe experiments in his fe- 

 cond letter; and I fliall here give a more particular account 

 of them. 



Having placed a completely or only half-prepared frog as 

 ufual in two glaiVes of water, take a very clean bow of filver. 

 (it will be beil when it has been walhed with water from the 

 glalles), and immerfe both ends of it at once, or the one after 

 the other, in the glaflcs, no agitation of the frog will be oc- 

 cafioned. Repeat the experiment, after you have daubed over, 

 one end of the bow with the white of an egg, liquid glue, 

 faliva, mucus, blood, a folution of tartar, or any other fluid 

 orconduelingfubdancefutriciently diflevent from pure water. 

 Firll, iunnerfe the pure end, or that moi(lened merely with 

 water, in the water of one of the glalVes ; and afterwards the 

 other end, daubed over with the above fubftances, in the 

 water of the other glafs ; you will then infallibly produce a 

 oonvullive movement in the frog, and fevcral times in fuc- 

 ceffion, if you draw oufthc bow and again inmierfe it unti^ 

 nothing more of the above fubilances is left adhering tg the 

 metal, or until the mefal, with its ends in both tlie glafles, 

 touches only pure, or nearly pure, water. Daub both the 

 above fublla.ices uniformly over both ends of the bow, anci 

 immerfe them at the fame (\n\c in both the glalTcs of water,, 

 and no convulfions will arife. They will often be produced 

 in nev.ly prepared and hio;hlv irritable frogs, when the faline 

 fluid, or, in general, the iubftanre with which the two ends 

 of the bow are daubed over, is not pcrfeftly the fame, or 

 -when the fvibftance at the one end is more diluted than at 

 the other, &c. Wath and clean carefully tiie one end of the 

 bow, daub over the other more or Icfs, and convullions will 

 \)t again produced as foon as the circle is in^de ppavplete by 

 " ^ ' ■ ■ thti 



