3G6 SJR THOMAS R. FRASER AND MR ALISTER T. MACKENZIE ON 



those of the left (unprotected) thigh were strongly acid. Three hours 1 5 minutes after 

 injection, galvanic stimulation of the right (protected) sciatic nerve with the secondary 

 coil at 100 mm. caused a contraction of the right gastrocnemius, whereas galvanic 

 stimulation of the left (unprotected) sciatic nerve at zero caused no movement of its 

 gastrocnemius. Three hours 18 minutes after injection, the gastrocnemii were exposed ; 

 the right (protected) gastrocnemius was of a reddish colour ; the left was quite pale and 

 firmer than the right. Three hours 20 minutes after injection, the right (protected) 

 gastrocnemius contracted when directly stimulated with the secondary coil at 100 mm., 

 while the left (unprotected) gastrocnemius did not contract when directly stimulated 

 with the secondary coil at zero. Three hours 45 minutes after the injection, galvanic 

 stimulation of the right (protected) sciatic nerve with the secondary coil at 80 mm. 

 caused a contraction of the right gastrocnemius, while galvanic stimulation of the left 

 (unprotected) sciatic nerve even at zero caused no movement of its gastrocnemius ; 

 and when directly stimulated, the right (protected) gastrocnemius contracted with the 

 secondary coil at 30 mm., but the left (unprotected) gastrocnemius did not contract 

 even with the secondary coil at zero. Nine hours 45 minutes after the injection, 

 galvanic stimulation of either sciatic nerve or of either gastrocnemius at zero gave no 

 result ; sections of both gastrocnemii were very acid to litmus, and there was general 

 rigor present throughout the body, though least marked in the right (protected) limb. 



In this and other similar experiments, the spinal reflex disappeared within 1 hour 

 after the injection of the extract, both in the protected and in the unprotected sides. 

 In the above experiment, the heart's ventricle was finally paralysed 30 minutes before 

 the spinal reflex had disappeared. Experiments in which the heart's movements and 

 the blood circulation are stopped by ligaturing the base of the heart, show that the 

 reflex function of the spinal cord persists for at least 1\ hours after complete arrest 

 of the heart. It seems probable, therefore, that the relatively early disappearance of 

 the spinal reflex is due to a direct action of S. sarmentosus on the cord itself. 

 The conductivity of the motor nerves is not destroyed until several hours after 

 the administration of the extract. Three hours after the injection, a cut surface of 

 the muscles of the unprotected thigh was strongly acid, whereas a section of the 

 muscles of the protected thigh was only feebly acid in reaction. 



(b) Sensory Nerves. 



In order to investigate the effects of the extract on afferent nerves, large frogs 

 {I 'ana esculenta) were used. Their brains were destroyed down to the level of a line 

 joining the posterior margins of the eyelids, and the experiments consisted in observing 

 after what interval of time the pelvic extremities were withdrawn from a solution 

 of 1 in 500 sulphuric acid in water — before and after the immersion of one foot in a 

 solution of the extract of S. sarmentosus. Immediately on withdrawal the foot was 

 washed. Unless otherwise stated, the limbs were in every case immersed in the acid 



