236
any case which is fit for an operation, unless it is excessive, that is to say, unless an over-dose
of chloroform is inhaled.
The facts brought out by the manometer experiments of the Commission, which can be
proved from the tracings, are:
1. "Chloroform, when given continuously by any means which ensures its free dilution
with air, causes a gradual fall in the mean blood-pressure, provided the animal's respiration is
not impeded in any way, and it continues to breathe quietly without struggling or involuntary
holding of the breath. As this fall continues, the animal first becomes insensible, then the
respiration gradually ceases, and, lastly, the heart stops heating (ride Experiment 169: Ludwig
and Fick tracings). If the chloroform is less diluted the fall is more rapid, but it is always
gradual so long as the other conditions are maintained; and, however concentrated the
chloroform may be, it never causes sudden death from stoppage of the heart."
2. Chloroform has no power of increasing the tendency to either shock or syncope
during operations. Every operation that ingenuity could suggest, or that has ever been sup-
posed to be dangerous under chloroform, was performed by the Commission in every stage
of chloroformisation, without any effect upon the heart, the pulse, or the blood-pressure.
3. The Commission found, however, that struggling during chloroform inhalation, or
anything which interfered with the breathing in any way, such as holding the breath or asphy-
xia, produced irregularities in the circulation and in the action of the heart (ride tracings of
Experiment 148). Even such slight interference a s is brought about by forcibly pulling the
tongue forward had this effect ( ride Tracing 185). I n fact, pulling the tongue, which is
constantly done when patients are supposed to be in danger from chloroform, was the only
proceeding short a direct irritation of the vagus that appeared to produce shock. This would
have been thought very paradoxical had it not been that previously. when Experiment 65 was
reached, Dr. Bomford had proposed that the heart should be inhibited by electrical irritation
of the vagus during chloroform poisoning, as he believed it would prove beneficial by postpon-
-ing or preventing the fatal effects. If Tracings 65 and 117 a re examined, it will be seen that
inhibition of the heart's action and slowing of the circulation, with rapid fall of pressure,c a u s e d
by irritation of the vagus, proved to be a safeguard, exactly as Dr. Bomford had anticipated,
rather than a danger.
4. Following up the discovery regarding the vagus, the Commission found that an
effect precisely similar to that caused by electricals t i m u l a t i o n o f t h e v a g u s i s p r o d u c e d t h r o u g h
the same nerve: ( a ) in the holding of the breath, which occurs in the early stages of chloro--
form administration ( ride Experiment 148: Fick I. and II., readings 2, 4. 6 8, 9. and 11):
( b ) i n a s p h y x i a
( r i d e
E x p e r i m e n t
1 6 1 :
F i c k 1 . r e a d i n g s
1 4 , 1 5 , 1 6 ,
a n d 1 7 : a n d E x p e r i m e n t
156: Fick I., reading 5); and (c) sometimes after the respiratory centre is paralysed in the
later stages of chloroform poisoning ( ride Experiment 148: Ludwig III., from 4 . 5 to 4 . 7:
and Experiment 178, all tracings). The same effect is produced in man by identically the
s a m e c a u s e s , a n d i s w h a t T H E L A N C E T o f M a r c h 2 n d . 1 8 8 9 , w r o t e a s o f " p r i m a r y a n d