1889-90.] Mr Dott and Dr Stockman on Morphine. 329 
muscles are also diminished somewhat in irritability, but not to 
anything like the same extent as the nerves. 
1.5. — Sciatics not excitable at 0. Muscles contract fairly well 
to moderate current. 
In another frog, when 0‘0425 grm. in cub. cent, -water was 
injected into the abdominal aorta, the sciatics were inexcitable to 
strongest current in 1 1 minutes, while the muscles of the legs were 
still quite excitable to direct stimulation. Small doses, such as 0*01 
grm., given in same way had a scarcely appreciable effect on the 
motor nerves. 
In another frog the following experiment -was performed as con- 
firmation. 
Expt. 4. — Frog pithed ; left femoral artery tied ; sciatic nerves 
excitable at 220 mm. 
2.28. — 005 grm. morphine hydrochlorate subcutaneously in 
solution. 
3.40. — Both nerves excitable at 220 mm. 
The frog passed through the narcotic and tetanic stages. Next 
day completely exhausted. Left (protected) sciatic nerve stimulated 
at 1 00 mm. gives good contraction of leg muscles ; right (unpro- 
tected) sciatic at 0 mm. gives scarcely perceptible twitch of muscles. 
In this experiment both sciatic nerves were subjected to the ex- 
haustion consequent on the tetanus ; but the right nerve, in addition, 
was exposed to the action of the morphine circulating in the blood. 
The protected nerve diminished very much in excitability (in con- 
sequence of the tetanus plus the cutting off of its blood supply), but 
the unprotected nerve wholly lost its excitability, and this difference 
can only be attributed to the action of the morphine on the latter. 
On repeating Vulpiap’s experiment on rabbits, we got (contrary 
to his results) paralysis of the motor nerves. Thus — 
Expt. 5. — Rabbit was put under ether. At 12.5 the right 
femoral artery was tied and the right sciatic nerve divided. A 
cannula was inserted into the left femoral artery, and the left sciatic 
nerve divided. Both nerves excitable at 90 mm. 
12.10. — 0*2 grm. morphine hydrochlorate was injected into the 
left femoral artery. 
12.20. — R. sciatic nerve quite excitable at 90 mm. L. sciatic at 
70 mm. gives very feeble twitch of muscles. 
