154 ON ANAESTHETICS 
the facts to be in the main as Dr. Warren has given them, the case may probably 
be fairly stated by saying that ether, being less potent, is less liable to cause 
death from mismanagement. But the rules for the satisfactory use of chloro- 
form are so simple that mismanagement is really inexcusable ; and if we had 
nothing else to consider than the question of safety, chloroform would probably 
in all cases maintain its superiority over ether. There is, however, another 
point in which a great advantage has been lately claimed for the original anaes- 
thetic. The vomiting which is so frequent after chloroform is generally only 
a matter of more or less inconvenience. But in the special case of ovariotomy 
the disturbance of the abdomen thus occasioned is thought to have sometimes 
been the cause of death. Dr. Thomas Keith, whose remarkable success in that 
operation is well known, was led to try sulphuric ether, in the hope that it might 
prove less objectionable in this respect, and the result has been in the highest 
degree satisfactory, so that whereas with chloroform vomiting was the general 
rule, it now seldom occurs in his practice. Dr. Keith has also ascertained 
that if truly anhydrous ether be employed, it can be given so as to produce 
its effect almost as rapidly as chloroform, and without waste of the material, 
by simply pouring a little of the liquid occasionally upon a piece of flannel con- 
tained in a cup-shaped vessel adapted to the mouth and nose, with a small 
aperture for the entrance and exit of air. Hence, as there are various other 
operations in which the avoidance of vomiting is a matter of great moment, 
sulphuric ether seems likely to reassume an important place as an anaesthetic. 
Nitrous oxide, which we had looked upon as of mere historical interest, 
as a kind of pioneer in anaesthesia, has also been revived of late years and turned 
to practical account, chiefly through the exertions of Dr. Evans, an American 
dentist residing in Paris. It is a remarkable fact, that when inhaled unmixed 
with atmospheric air, it fails to produce the excitement to which it owes the 
name of ‘laughing; gas’, but merely throws the patient very rapidly into 
a condition of complete coma, attended with great lividity of the face, and 
staring dilatation of the pupils, presenting a very alarming appearance when 
seen for the first time, but, as experience shows, free from danger, subsiding as 
rapidly as it supervened, and leaving in the great majority of cases no trace of 
sickness or other unpleasant effects. The agent has recently been rendered 
much more portable by keeping it stored in the liquid form in a strong cast-iron 
bottle, from which, by turning a stopcock, the gas is supplied to an india-rubber 
bag, large enough to contain about an average dose for producing insensibility. 
When this is exhausted, the balloon can be refilled in the same way as often as 
may be desired, and thus it is possible by a series of intermitted administrations 
1 See Lancet, August 20, 1870. 
