EXCITATION AND CONDUCTION 65 
case the decrease of carbon dioxide production is decided. 
Table VIII illustrates quantitatively the difference in 
carbon dioxide production under these different con- 
ditions. The interesting results with 3 per cent and 
4 per cent solutions will be considered later. 
TABLE VIII 
EFFECTS OF CHLORAL HyDRATE ON CLAW NERVE OF SPIDER CraB, Libinia canaliculaia 
TREATED By AMOUNT OF COz 
AFTER CHANGE PRODUCED BY 
Enxcts ON Return to | 1% WEIGHT IO MG. OF THE 
Concentra- | For | Excitasriry Sra-WATER IN Io NERVE INTO 
tion in How Minutes MINUTES 
Sea-Water | Long 
oper cent...| 10 min.| Excitable No change | 7.9X10~7 g.at20°2 
o per cent...} ro min.| Inexcitable No change | 5.7X10~7 g. at 22° 
©.4 per cent.| 10 min.| Becomes more] Excitable No change |11.5X10—7 g.at20°4 
‘ irritable _ ‘ 
I per cent...| 10 min.| Slow narcosis | Excitable No change | Not determined 
2 per cent...| 10 min.| Partial or com-| Good return] Very. slight} 4.2X10—7 g.at22°s 
plete narcosis} gain 
3 per cent...| 10 min.| Completely Fair return | 25 per cent] 2.8X10— 7 g.at23°5 
narcotized gain 
4 per cent...} 10 min.} Completely Partial or 50 per cent] 3.6X10—7 g.at23°s 
narcotized doubtful gain 
return 
Is the decrease of carbon dioxide due to narcosis ?— 
The results given above establish beyond a doubt that 
during treatment with narcotics, in concentrations which 
produce a reversible loss of irritability, the carbon 
dioxide output of a nerve is greatly reduced. The 
differences thus produced are far beyond the limits 
of experimental error and there can be no suspicion that 
the phenomenon is the result of faulty observation. The 
question might be raised, however, whether this diminu- 
tion is directly related to the narcosis, or whether it 
might not be due to some factor casually introduced 
