REMARKS ON THE EFFECTS OF .ETHER. 
261 
but from the slowness of the inhalation, the full effect of depriving 
of sensation was not arrived at, as when pricked at different stages 
of the experiment feeling was plainly shewn. Neither did the 
pulse rise, indicating the full effect of the vapour ; the eyes became 
rather fixed, and sleep, or apparent sleep, shewed itself ; the pulse 
did not rise above 65, and remained voluminous and soft, as in 
the former instance. 
These two latter experiments are of a totally different cha- 
racter from the four preceding ; but it is shewn that, though 
the effect was more in accordance with that which has been 
stated to be produced by others through the agency of aether, two 
things are manifest ; first, the quantity of aether that is required 
to produce vapour sufficient to induce a requisite degree of influ- 
ence is very large ; secondly, that unless a continuous stream of 
aether vapour is inhaled up to the production of the full effect of 
prostration, it will take a much longer time and consume a larger 
quantity of aether than it would in the case of a larger quantity of 
aether being produced at once ; and this longer period of producing 
the full effect, is, further, not attended with any advantage to the 
operator or the animal : the pulse rises as high, the system suffers 
as much, and the effect does not appear to be of a more lasting 
character after it has been produced, but rather the reverse, to say 
nothing of the greater expense of the operation. 
There is one other point which must not be overlooked, which is, 
that the effect of aether is cumulative , if applied too often, or with- 
out long intervals between ; that is to say, that so great a shock is 
given to the system by the operation of so powerful an agent, as to 
render its action exceedingly uncertain in those cases in which it may 
be requisite to employ it more than once ; for though it may not at 
the time of its second or subsequent exhibition shew more than 
its ordinary effect, yet such may be the condition of the system 
itself, that it may not be able to bear up against the repeated exhi- 
bition of an injurious agent, and hence not have a sufficient degree 
of reactive power to overcome its secondary consequences. 
Another striking point is the extraordinary difference that is 
shewn in the nature of the action induced. In two of the animals 
operated on, the greatest degree of violence was manifested ; in the 
other two not a single symptom of violence was evinced. This 
appears to be an anomaly, but is plain enough, if more closely 
examined into, and strictly within the bounds of explanation ; but 
before we enter into this part of the question, it will be as well to 
shortly review the arrangement of the nervous system, and inquire 
which of the component parts of this important system is the one 
really affected by this terrific agent. 
The nervous system is divided into two great divisions, and one 
VOL. XX. N n 
