240 
DRS. T. L. BRUNTON AND J. T. CASH OH CHEMICAL CONSTITUTION, 
Fig. 2. Frog poisoned by tetramethyl-ammonium iodide. 
a. Ligatured leg. Ten stimulations* (direct) of gastrocnemius, one stimu¬ 
lation every 1'5 S . 
b. Poisoned leg. Ditto. 
Fig. 3. Frog poisoned by large dose ('2 grm.) amyl-ammonium iodide. 
a. Ligatured leg. Ten stimulations (direct) of gastrocnemius, one stimula¬ 
tion every L5 S . 
b. Poisoned leg. Ditto. 
c. Poisoned leg. Single curve, indirect stimulation. 
Fig. 4. Frog poisoned by trimethyl-ammonium iodide. 
a. Ligatured leg. Ten stimulations (direct) of gastrocnemius ; curves of 
direct and indirect stimulation are equal; one stimulation 
every 1'5 S . 
b. Poisoned leg. Ditto. Direct stimulation. 
c. Poisoned leg. Ditto. Indirect stimulation. 
Fig. 5. Frogs poisoned by tetraethyl-ammonium iodide. 
a. Ligatured leg. Single stimulation of gastrocnemius (direct). 
b. Poisoned leg. Ditto. The nerve is no longer irritable. 
c. Case of profound poisoning. Direct stimulation of gastrocnemius. 
Fig. 6. Frog poisoned by dimethyl-ammonium sulphate ('25 grm.). 
a. Ligatured leg. Direct and indirect stimulation. 
b. Poisoned leg. Direct stimulation. Nerve no longer irritable. 
Fig. 7. Frog slightly poisoned by trimethyl-ammonium sulphate (T grm.). 
a. Ligatured leg. Tetanus 5 s , direct stimulation. 
b. Ligatured leg. Ditto, indirect stimulation. 
c. Poisoned leg. Tetanus 5 s , direct stimulation. 
cl. Poisoned leg. Ditto, indirect stimulation. 
Fig. 8. a. Normal gastrocnemius. Direct stimulation. 
b. Ditto. After 5 m in 1 per cent, chloride of rubidium solution. 
c. Ditto. After 15 m in '75 per cent, chloride of calcium solution. 
Fig. 9. a. Normal gastrocnemius. Direct stimulation. 
b. Ditto. After 20 m in 1-1000 chloride of ammonium solution. 
Fig. 10. a. Normal gastrocnemius. Direct stimulation. 
b. Ditto. After 30 ,n in 2 per cent, solution chloride of sodium. 
c. Ditto. After 45 m in ditto. 
Fig. 11. Frog poisoned by *02 grm. chloride of caesium. 
a. Ligatured leg. Direct stimulation. 
b. Poisoned leg. Ditto. 
Fig. 12. a. Normal gastrocnemius. Direct stimulation. 
b. Ditto. After 15 m in T per cent, chloride of ammonium. 
* All single stimulations are by an opening maximal induction stock. 
