MR. J. PRIESTLEY ON THE PHYSIOLOGICAL ACTION OF VANADIUM. 547 
to taste produces reflex movements, on dipping the frog’s toes into it, in 
from 4 to 5 seconds. A healthy frog, treated in the same manner, contracted 
, its lens after its toes had been immersed in the acid for 2 seconds, 
h. m. ° 
4 15. The same acid solution induces reflex movements in 10 secends. 
4 25. Decapitated, and irritated the end of the exposed cord ; movements resulted in 
the leg-muscles as soon as the secondary coil stood at 8. 
4 30. A healthy frog had been decapitated and allowed to recover from the shock of 
the operation ; its cord was now irritated in the same way ; movements 
resulted when the secondary coil stood at 11. 
4 30. On again testing the reflex irritability of the poisoned frog in the manner above 
indicated and with the same solution of acid, no indications were obtained, 
even after the feet had been immersed for 100 seconds. 
This experiment indicates a general impairment of the power of reflex action, while 
the function of the cord as a conductor of stimuli remained intact to all intents, the 
apparent difference in the degree of irritability of the cord in the normal and in the 
poisoned frog] being most probably due to the deficient aeration in the latter case, a 
circumstance only indirectly attributable to the poison. 
Exp. LXXII.— May 27, 1874. 
Frog. — Weight 23 grms. 
Dose 1 cub. centim. of the 5 per cent, solution (50 milligrammes 
h m V 2 0 5 ), injected subcutaneously. 
2 40. Injection complete. 
2 55. Respiration seems almost to have ceased ; the frog lies quite flat on its belly as 
if weak. Reflex action, after immersing the toes in a T per cent, solution 
of H 2 S0 4 , in 25 seconds. 
On being put into a large beaker of water, the frog sank immediately and 
did not attempt to swim. It can jump quite well, however. 
3 0. Reflex actions induced by strong acetic acid after 5 seconds. 
3 5. Lies quiet : moves of its own will. 
3 7. On touching the cornea the eyelid did not move until after some time. Sluggish 
movements result on pinching the leg, also on gently rubbing the thigh with 
the point of a lead pencil. 
3 20. On touching the cornea with the points of the electrode of a secondary coil 
through which strong interrupted currents were passing, distinct movements 
of the eyelids were observed. 
3 30. On lifting up the hell-jar under which the animal had been lying, the frog 
moved spontaneously. Pinching induces sluggish reflex actions. 
A solution of H 2 S0 4 (distinctly acid to taste) caused contractions of a 
reflex character in 5 seconds. 
4 F 2 
