PRESENT STATE OF ORGANIC ELECTRICITY. 31U 



tlie labours of Volta. Its history presents three distinct lines 

 of research — that of the special electrical organs of the fish, 

 commencing with the discovery of AVal.sh in 1772,* that of 

 the electrical properties of muscle and nerve, starting from 

 the fundamental experiment of Galvani in l78G-94,+ and tliat 

 of the electrical phenomena of membranes and glands, intro- 

 duced by DomiL' in 1834. J 



The results wliich have ultimately been attained in these 

 three directions -will now be briefly examined ; but in order to 

 obtain a more comprehensive view they shall be taken up in 

 the reverse order. 



Electric rhcnomcTia in connection vntJi Membrane and 

 GL.VND. — The experiments of Donne are now alluded to only 

 because they were the first which proved electric disturbance 

 in connection with secreting membmne and .structure. He 

 found that when the electrodes of the galvanometer were 

 applied respectively to the raucous membrane of the mouth 

 and to the skin, the needle deviated 15°, 20°, or 30° ; the 

 former being negative, the latti-r positive. In the same 

 manner, ^lien the instrument was ap}»lied between the mucous 

 membrane of the stomach and the gall-bladder, or interior of 

 the liver, the needle deviated 30°, 40°, or 50°. 



Donn6 attributed these electric effects to tlie acid and alka- 

 line properties of the secretions with which the electrodes 

 were respectively in contact. ^[atteucci,§ again, while ad- 

 mitting the correctness of Donne's experimental results, attri- 

 buted, asDrs. WoUastonll and Thomas YoungH had previously 



♦ " Of the Electric Property of the Torpdo."— /7u7. Trans. 1773. 



+ De Viribus ElcctrkUatis in Molu Muxidttri CvmmaUariua ; Bologna, 



1791. 



t Ann. de Chim. et de Phys. torn. Ivii. 1834. 



§ //'///. toin. Ivi. 



II rhit. Maij. vol. x.x.xiii. " On tlie Agiiifv of Electricity on Animal Secre- 

 tions." 



H Youug. SijUiibtu of iM-lurcs ori Mfdirine. 



