CHAP. VIU. MUSOUIiAE AND NEEVOUS TISSUES. 79 



solutions : — Five drops of strong sulphuric acid to 

 one ounce of distilled water, formed the acid solution ; 

 one drachm of liq. potassse (Phar. Londin.) to one 

 ounce of distilled water, formed the alkaline solution ; 

 and one drachm of common salt to one ounce of 

 distiUed water, formed the neutral solution. 



Whenever one electrode was moistened with the 

 acid solution, this was positive to the other on what- 

 ever parts of the muscle or nerve they were placed. 

 When both electrodes were moistened with the so- 

 lution, the indications were doubtful. 



When the alkaline solution was employed in the 

 same manner, the electrode in contact with the 

 external surface of the muscle or nerve was positive 

 to the other ; it very rarely happened that the elec- 

 trode in contact with the tranverse section indicated 

 a positive condition, when the other electrode alone 

 was moistened with the solution. 



With the solution of salt, similar effects were 

 observed as with the alkaline solution; and from 

 these facts we cannot but infer that these two 

 solutions, the alkaline and the salt, acted merely as 

 a conducting liquid, whilst the acid solution acted 

 chemically upon the animal substances. It cannot 

 be supposed, or at any rate be believed, that the 

 sarcolemma or neurilemma acted, in these instances, 

 as an acid substance, merely for the purpose of 

 explaining or accounting for the existence and di- 

 rection of the current, since the alkaline solution 

 would have destroyed its acid reaction. 



