PKESENT STATE OF ORGANIC ELECTRICITY. 319 



the 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 Walsh in 1772,* that of 

 the electrical properties of muscle and nerve, starting from 

 the fundamental experiment of Galvani in 1786-94,1 and that 

 of the electrical phenomena of membranes and glands, intro- 

 duced by Donne* in 1834 1 



The results which 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 PJienomena in connection with MEMBRANE and 

 GLAND. The experiments of Donne are now alluded to only 

 because they were the first which proved electric disturbance 

 in connection with secreting membrane and structure. He 

 found that when the electrodes of the galvanometer were 

 applied respectively to the mucous membrane of the mouth 

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

 former being negative, the latter positive. In the same 

 manner, when the instrument was applied between the mucous 

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

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



Donne* attributed these electric effects to the acid and alka- 

 line properties of the secretions with which the electrodes 

 were respectively in contact. Matteucci, again, while ad- 

 mitting the correctness of Donnas experimental results, attri- 

 buted, as Drs. Wollaston 1 1 and Thomas Young IF had previously 



* " Of the Electric Property of the Torpedo. "Phil. Trans. 1773. 



t DC Viribus Electricitatis in Motu Musculari Commentarius ; Bologna, 

 1791. 



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



Ibid. torn. Ivi. 



II Phil. Mag. vol. xxxiii. " On the Agency of Electricity on Animal Secre- 

 tions." 



II Young. Syllabus of Lectures on Medicine. 



