82 
POPULAR SCIENCE REVIEW. 
its truly poisonous effects (carrying these to a certain, fixed 
limit_, wtiicli is still at a safe distance from death) so as to 
render the patient completely insensible to the pain of the 
surgeon^s knife. As the action of this ansesthetic presents a 
fair example of the general progress of narcosis when rapidly 
induced_, it may be as well to describe the series of events 
which occur in an ordinary inhalation. 
It is now fully proved that for safety it is quite necessary 
that such precautions shall be adopted as will ensure that the 
air breathed by the patient shall not contain more than 3' 5 
per cent, of chloroform vapour. These precautions having 
been taken^ the inhalation is pursued with great regularity, 
the operator taking care to assure himself that the pulse keeps 
up its tone sufiiciently, and that the face and lips do not 
become blanched. The patient usually exhibits one mark of 
apprehensive nervousness very strongly, namely, an abnormal 
quickness of breathing altogether out of proportion to the 
pulse rate, and owing, doubtless, to his attention being ner- 
vously directed to the respiratory organs. This abnormal 
quickness of breathing is greatly diminished by the stimulant 
effect which the chloroform exerts during the short initial 
period in which as yet only a minute quantity has entered the 
blood. As soon as true narcosis commences the pulse rises in 
frequency; simultaneously with this the intellect begins to be 
disturbed, the patient loses (or only retains feebly) the sense 
of present things, while occasionally (the restraint of prudence 
and morality being removed by the commencing brain-palsy) 
he becomes violent or indecent in his talk ; at tlie same time 
that palsy of the tongue begins to interfere with articulation. 
Meantime, although from the patienks recumbent posture this 
has not been perceived by the bystander, palsy of sensation 
and motion has commenced in the lower limbs, and now pro- 
ceeds to invade the upper, and the patient may sink quietly 
into general muscular and sensory paralysis and profound 
unconsciousness. But often the last remnants of mental 
action display themselves in an explosion of passion which 
causes more or less powerful voluntary struggles on the part 
of the patient ; and, even after voluntary action has ceased, 
the advancing narcosis may, and not unfrequently does, 
produce spasmodic rigidity of the muscles, and, occasionally, 
epileptiform convulsion ; all which phenomena of excite- 
ment,^^ as they have been absurdly called, are really the direct 
(though not the inevitable) consequence of the advancing 
nervous paralysis. The pupil, in the lesser degrees of nar- 
cosis, is contracted ; but if the process is carried to a profound 
degree, as is necessary in operations on very sensitive parts 
(like the toenail-matrix, for instance), wide dilatation of the 
