MR. J. PRIESTLEY ON THE PHYSIOLOGICAL ACTION OE VANADIUM. 499 
i. Action of the Poison when introduced into the System by subcutaneous injection. 
On Frogs. 
Exp. VII. — December 3, 1873. 
Weight 24 grms. 
Dose • 5 cub. centim. of the 5 per cent, solution (25 milligrammes V 2 0 5 ), 
h. m . injected under the skin of the back. 
2 25. Injection complete : frog very active. 
3 0. Normal to all appearance, and active. 
3 10. Not so active, but otherwise normal. 
3 15. Quieter. 
3 20. Still moves limbs freely ; no signs of paralysis. 
3 25. Conscious ; respiration has ceased. 
3 35. Quiet; moves on being irritated. Conscious; lower jaw has fallen. No 
breathing at the lungs. 
3 40. Lower jaw has sunk more ; moves on being irritated ; still not breathing. 
3 55. Cornea sensitive ; attempts to move when stirred. 
4 15. Still capable of moving. 
5 0. On being stirred the frog makes vigorous efforts to leap, but does not seem 
able to grasp the table firmly enough, although its muscular contractions 
are sufficiently energetic. 
5 50. Nearly dead ; does not retract its limbs after they have been spread out, as it 
did some time previously; still attempts. to move a little when stimulated. 
6 5. No movement at all on being irritated. 
The frog was then opened ; the heart was contracting perfectly. 
Liver very dark in colour. 
Muscular and nervous irritability quite normal on applying electrical 
stimulation. On snipping through the cord the legs were observed to 
contract. 
In this experiment it may be noticed that complete paralysis of voluntary muscles 
occurred in 3 hours 40 minutes after injection ; that the poison began manifestly to 
act within 1 hour of injection ; that the respiratory muscles were the first to cease 
acting ; that consciousness remained for some hours after respiration had ceased ; that 
the heart was not affected ; that muscular and nervous irritability remained perfect on 
direct stimulation by induction-currents ; and that the cord seemed capable of conducting 
stimuli. 
Exp. VIII. — January 21, 1874. 
Weight (a small English frog). 
Dose 1 cub. centim. of a '5 per cent, solution prepared from the ordinary 5 per 
cent, solution (i. e. 5 milligrammes V 2 0 5 ), injected under the skin of the 
back. 
Note. — A small amount was lost during injection. 
3 z 2 
