98 Messrs. T. L. Brunton and J. Fayrer on the [Jan. 22, 



up very slowly with a wriggling motion. Pressure on the right foot causes 

 no movement whatever. 



12.40. Acetic acid applied to a forearm causes vigorous movement in 

 it and also in left hind leg. 



1. Acetic acid to right hind foot causes no movement. Applied to left 

 hind foot it causes vigorous movements in both forearms and left hind leg. 



1.12. A ligature was applied to the left thigh in a similar manner to 

 that on the right, so as to cut off the circulation in the left leg also, and 

 thus bring the two legs as much as possible under the same conditions. 

 The general condition of the frog is much the same as before : but the 

 reflex action produced by irritation of the cornea is slighter. 



1.24. Acetic acid applied to right forearm. Slight movement occurs 

 in right hind leg alone. When applied to left forearm it caused slight 

 movement in that arm alone. 



1.35. Acetic acid applied to both feet, both forearms, and to the nose 

 caused no motion anywhere. Both sciatic nerves were now laid bare along 

 a considerable portion of their course. It was found that, although the 

 right sciatic had not been included in the ligature, it had been tightly 

 constricted by the fascia at the place of ligature. Sciatic nerves irritated 

 by an induced current. 



Distance of secondary 

 Leg. from primary coil. 



Left. 0* No contraction of muscles of leg. 



E/ight. 32'0 Distinct contraction. As this might 



possibly have been due to the left 

 sciatic being injured by the ligature 

 more than the right, both sciatics were 

 exposed further, and irritated quite 

 below the points of ligature and just 

 above the knee. 



Eight. 37'5 Distinct contraction. 



Left. 7*0 No distinct contraction. "When the 



muscles were irritated by single in- 

 duced shocks, applied to them directly, 



Single shock. 7.5 they contracted almost equally. 



In this experiment, the right sciatic nerve had been injured by the ope- 

 ration of ligaturing ; and thus the effect of the poison on the other limb 

 as compared with the right one was less manifest. Notwithstanding this 

 it moved, and the other limbs did not, when the right arm was irritated. 

 The difference between the irritability of the sciatic nerves when the 

 muscles of the legs themselves were almost equally irritable, shows, in a 

 marked manner, the influence of the poison on the motor nerves. 



Experiment XL. 

 May 14th. Erog ligatured round the middle, excluding lumbar nerves. 



