548 MR. J. PRIESTLEY ON THE PHYSIOLOG-ICAL ACTION OF VANADIUM. 
h. m. 
3 36. Reflex activity tested as above ; movements occurred after immersion for 
10 seconds. 
3 42. Reflex actions occurred after an immersion of 20 seconds. 
3 47. On exposing the cord high up in the back and irritating, distinct movements 
occurred when the secondary coil was at 17. 
In this experiment reflex action was distinctly impaired ; but it may be remarked 
that voluntary movements occurred long after that impairment had distinctly begun ; 
i. e. long after reflex irritability had begun to disappear, the cord was capable of con- 
ducting impressions from the brain. 
The remaining experiments on the functions of the cord were tabulated in order to 
show clearly the diminution in reflex irritability. In all cases the frogs had their cords 
cut at the atlanto-occipital articulation, and the parts above the points of section 
destroyed, in order to get rid of their influence. In testing reflex irritability dilute 
H 2 S0 4 was used as a stimulus, the frog being suspended by the head in such a manner 
as to allow the toes (or feet) to dip below the surface of the acid; the seconds were 
counted which intervened between immersion and the occurrence of contraction, and 
taken to indicate the degree of irritability. The frogs in experiments LXXIII., LXXIV., 
and LXXVI. were poisoned by the injection of sodium vanadate in solution under the 
skin ; the frog in experiment LXXVII. was similarly injected with pure water, and its 
reflex irritability used as a standard. Experiment LXXIII. is given in detail to illus- 
trate the method ; but its results were exactly confirmed by the succeeding experiments, 
as will be gathered from the brief notes attached to the latter. 
Exp. LXXIII.— June 2, 1874. 
Frog. — Weight 34 grms. 
Dose *5 cub. centim. of the 5 per cent, solution (25 milligrammes 
k. m V 2 0 5 ), injected under the skin. 
June 1. 7 30 p.m. Cord of frog divided and brain destroyed. 
June 2 : — 
Time. 
Bemarks. 
Strength of acid 
per cent. 
Number of se- 
conds between 
immersion and 
contraction. 
Mean number 
of seconds. 
h. m. 
11 45 a.m. 
Normal reflex actions 
2 
2 
11 50 
,, ,, „ 
1 
1 
„ „ „ 
1 
1 
11 52 
„ ,, „ 
1 
1 
11 55 
„ „ 
•5 
3 
,, „ 
•5 
2 
1-2 
12 10 
Injection complete. 
12 10 
Tips of toes immersed 
•5 
8 
4 
4 
6 
12 15 
„ „ „ ..... 
•5 
4 
10 
6 
