374 Proceedings of Royal Society of Edinburgh. [sess. 
under consideration been replaced by chlorine. However that may 
be, we regard the physiological results obtained with this substance 
as of considerable value, as they indicate the general modification 
in the action of morphine caused by the substitution of chlorine 
for the hydroxyl groups. 
Physiological Action of Trichloromorphide. 
Frogs . — Trichloromorphide acts primarily on the central nervous 
system, causing depression of the spinal cord, followed by tetanus. 
It has, however, even in moderate doses, a marked paralysing effect 
on motor nerves, wdiich tends to obscure the tetanus while it lasts. 
The paralysis is, however, somewhat slow in appearing, and soon 
wears off, usually leaving the animal in violent spasm. In addition, 
trichloromorphide has some slight action as a muscle-poison. 
The following experiments show its action in all these respects : — 
Expt. 33. — Frog, 30 grms. 
12.8 — O'OOo. grm. trichloromorphide subcutaneously. 
12.12. — Keflexes slightly diminished. 
12.15. — Keflexes very distinctly depressed, but frog still moving 
about. 
12.20. — Sluggish; lies on back; pupils small. Keflexes slightly 
increased. 
12.25. — Slightest touch causes violent start. 
12.30. — Spontaneous tetanus, followed by great flaccidity. 
Slightest touch brings on tetanus. 
12.37. — How gives a mere twitch on stimulation. 
12.42. — Ho response on stimulation. Sciatic nerves inexcitable 
to strong electric current. 
Second day. — In violent tetanus. 
Third to fifth day.— In tetanus. 
Sixth day. — Dead. 
If the sciatic nerve of one leg be protected by tying the femoral 
artery, and 5 milligrms. be given, the protected nerve is not paralysed 
while all the others are. 
Expt. 34. — Frog, 30 grms. 
12.46 — 0‘01 grm. trichloromorphide subcutaneously under skin 
of back. 
12.58. — Has gradually become deeply paralysed. 
