Chap. 35.] to Animal Eleftricity. 359 



main in contact no flaih is obferved. Thefe curious 

 phenomena demonftrate the free communication which 

 fubfifts. between the feveral branches of the fifth pair 

 of nerves. 



The following curious fact is alfo taken from Dr. 

 Fowler's ingenious and entertaining book on animal 

 electricity. He laid a leech on a crown-piece of filver, 

 placed in the middle of a large plate of zinc. The 

 animal moved its mouth over the furface of the filver 

 without expreffmg the leaft uneafmefsj but having 

 ftretched beyond it and touched the zinc plate with its 

 mouth, it inftantly recoiled as if in the moft acute pain, 

 and continued thus alternately touching and recoiling 

 from the zinc, till it had the appearance of being ex- 

 tremely fatigued. When placed wholly upon the zinc, 

 it feemed perfectly at its eafe ; but when at any time 

 its mouth came in contact with the filver lying upon 

 the zinc, the fame expreffion of pain was exhibited as 

 before. With the earth-worm he found that the ex- 

 periment fucceeded flill more decifively. The animal 

 fprang from the zinc in writhing convulfions ; if, when 

 the worm ftretched itfelf forwards, one of the folds 

 came upon the zinc, it expreffed little uneafmefs in 

 eomparifon of what it fhewed when the point of its 

 head touched the zinc. 



Whether this influence, whatever it may be, is de- 

 rived from the metals alone, or whether the animals 

 contribute to its production, is not eafy to determine. 



On re-confidering the phenomena exhibited by this 

 newly difcovered influence, we mail perceive that in 

 fome refpets it remarkably refembles electricity, and 

 in others as remarkably differs from it. 



Like the electric fluid, it ftimulates mufcles to con- 

 traction. Like that, its progrefs is arrefted by glafs, 

 lealing-wax, Sfc. while it is conducted by metals, 

 A a 4 moifture, 



