ON THE PHYSIOLOGICAL ACTION OF THE METHYL CoMPpouNDs. 181 
being used, the other details were changed. The animal was allowed 
to pass through the stage of muscular excitement into the third stage of 
muscular relaxation. This stage reached, the current was transmitted 
through the body of the animal. The effect, again instantaneous, was not 
to destroy life, but to excite all the phenomena of apparent active life. The 
wings were moved as in the act of flight, motions attended with progressive 
or propulsive action were strongly marked, the breathing was quickened, the 
impulse of the heart was increased, and the temperature rose ; but when the 
current was withdrawn all these striking phenomena were withdrawn also, 
and the animal again slept inactive and prostrate, but ready to recover. 
For the sake of comparison another experiment of a similar character was 
carried out, in which, instead of reducing the animal body by the administra- 
tion of chloroform, the spray of ether was directed upon the cerebrum until 
the phenomena of entire unconsciousness and of muscular prostration were 
fully pronounced. Then the current from the coil was passed through the 
body as before, with the temporary development of the phenomena of mus- 
cular activity. 
The lessons taught by these experiments are in confirmation of all that 
has gone before. They prove how distinct a double action on the muscular 
organs is exerted by chloroform, and they indicate an independency of in- 
fluence upon the muscular and nervous systems, between insensibility, or I 
had better say unconsciousness, and deficiency of motor power, which I was 
not myself, previous to the experiments, prepared to recognize. It is clear 
that in the narcotism induced by chloroform, and perhaps by all other similar 
agents, the muscles can be called into action while the brain is virtually dead; 
we can, in short, supply the muscles with an artificial nervous energy. 
Dangers attending administration of Methyl or Ethyl Compounds. 
Recasting these experiments and putting the various facts in order, I have 
been led to consider from them the dangers which waylay the administrators 
of the methyl and ethyl compounds, the causes of these dangers, and the 
way to avoid them. 
And here, I think, is a primary truth, the basis of progress in the discovery 
of new agents:—that the danger in anesthesia does not lie in the produc- 
tion of sleep, nor even of deep sleep, but in the production, in the course of 
the process, of symptoms which, although the prime sources of danger, are not 
connected by any necessity with the anesthesia. I refer especially to the 
symptoms of muscular excitement and rigidity, followed, as we have seen, 
by decrease of temperature of the animal. 
Again, I think there is another truth hardly secondary, viz. that we 
already possess agents which by their action prove to us their power of pro- 
ducing anesthesia without exciting muscular rigidity, and without materially 
disturbing the animal temperature. If this be true, we ought as men of 
science to exclude at once from the list of safe anesthetics all such as on 
experiment are found to produce rigidity of muscle or vomiting (which is 
an indication of the same action), and reduction of beat by its transference 
into motion at a moment when the conditions for the liberation of force are 
most unfavourable. 
The exclusion here named would, I conceive, of itself save many lives, and 
would bring the danger of artificially induced sleep to the danger, and no 
more, of mere natural sleep. The only cause of accident would be in carry- 
ing the insensibility to the extreme of extinguishing life, an accident for 
which the administrator would be clearly culpable, and which, even now, 
