32 Mr H. F. Baxter on the Effects of Acid and Alkalies 



may be correct, it becomes necessary to obtain further evi- 

 dence than that afforded by the use of the electric current, 

 and for this purpose I employed chemical reagents in the 

 following manner : — 



It is reasonable to suppose, that by placing an acid and 

 an alkaline solution on different portions of a nerve con- 

 nected with the muscles, that some difference might be 

 obtained in the contractions, depending upon the relative 

 position of these solutions in regard- to the muscles. In 

 my first experiments the two limbs remained connected 

 with the spinal cord, but the contractions excited in one 

 limb, in consequence of reflex actions, rendered the results 

 doubtful. The following plan was consequently adopted : — 

 The two lower limbs being separated, a long portion of the 

 sciatic nerve was dissected out and placed on two portions 

 of bibulous paper, resting on distinct pieces of glass, and 

 the leg rested on another distinct piece of glass. The 

 bibulous paper, when well soaked, prevented the solutions 

 from running over the surface of the glass : the distances 

 between the place where the solutions were applied and 

 the muscles could be varied at pleasure ; but the piece of 

 glass upon wdiich the limb rested was higher than the 

 others, so as to keep the solutions from running down on to 

 the muscles. To prevent the nerve from being moved 

 during the contractions of the muscles, it was uecessary to 

 fasten the limb down, either by a ligature or by placing a 

 w^eight on the thigh bone. 



The limb in which the acid solution was nearest the 

 muscle will be designated by the letter a ; that in which the 

 alkaline solution was nearest to the muscle by the letter b. 

 I need scarcely add that the nerves should be placed on 

 distinct papers and glasses, otherwise a circuit would be 

 formed between the two nerves, if resting on the same 

 papers. 



The acids comprised the sulphuric, nitric, muriatic, and 

 the acetic acid. Three solutions of each were prepared, 

 varying in strength, and consisting — No 1, of 1 part of 

 acid to 10 of water ; No. 2, of equal parts of acid and water ; 

 No. 3, of concentrated acid. The alkaline solutions, com- 

 prising those of potash, ammonia, and soda, were formed as 



