207
used, a sudden fall of pressure was observed. It then behoved them to inquire how deaths
during the administration of chloroform were likely to occur, and how they were to be pre--
vented. They investigated the direct action of chloroform upon the heart. It was well known
that if chloroform were injected into ordinary striated muscle it became hard like a board, but
they found that injection of chloroform into the veins did not produce a distinct action on the
cardiac muscle fibre,—at any rate, not in anything like the degree they had anticipated. The
injection of both chloroform and ether into the veins was found to lower the blood-pressure,
but ether had a less effect than chloroform. It was found, however , t hat et her us ual l y caus ed
clothing of blood in the heart, and thus led to a fatal result. When ether and chloroform were
injected into the trachea they both produced a rapid fall of blood-pressure. It should be
remembered, however, that the action of chloroform in those two ways,—by injection into the
veins and into the trachea.—represended its toxic rather than its therapeutic effects. If the
vapour of chloroform were driven into the trachea after the stoppage of respiration, the heart
became paralysed; but when administered by s i m p l e i n h a l a t i o n a l o n e ,
w h e n t h e r e s p i r a t i o n
stopped all excess of chloroform was prevented from getting into the circulation, and the heart
in that case was not paralysed. But there were certain points about the matter which required
fuller consideration. An animal dying from paralysis of respiration after the stoppage
of regular breathing, make one or two violent gasps, and these might bring in enough chloro
-form to stop the heart’s action, There was some risk of this happening, b ut this risk only
occurred if the chloroform vapour was drawn in when the animal was in a state of asphyxia.
A tracing taken from an animal in this condition was found to be identical with one produced
by the Committee of the British Medical Association. There was a drop in the respiratory
curve, followed by slow action of the puke, and then a gradual rise again. This slow pulse
was due to vagus irritation ; and such a t r a c i n g c o u l d b e m a d e a t w i l l b y
i n d u c i n g s i m p l e
asphyxia, either by closing the dog’s nostrils, or, if a canula were in the trachea, by stopping
the end of the canula, o r b y
M a k i n gt
h e d o g b r e a t h e
p u r e c a r b o n i c a c i d g a s .
S u c h
a c o n d i t i o n
w a s n e v e r p r o d u c e d b y t h e a d m i n i s t r a t i o no
f c h l o r o f o r m
w i t h p l e n t y
o f
a i r , b u t
i t a l w a y s
occurred during , accidental asphyxia. Dr.Bruntonh a d
b e e n m u c h p u z z l e d a s
t o h o w t h e
Glasgow Committee had produced this tracing, and he sugguested an explanation. If, With a
canula in the trachea, artificial respiration Were being performed, a small quantity of blood
might run down into the bronchi and clot.It
might there form a valvular plug,and by
moving up and down produce an intermittent asphyxia and give rise to such a tracing.
s everal experiments Were tried on the effect of s hock, but no marked symptom of that condi
-tion could be produced. It was true that no experiments had been done without ether or
chloroform, but they concluded that such experiments Were not only painful but unnecessary.
They first put an animal under chloroform and extracted several teeth, but no symptom of
shock followed ; they then tried laying hold of the skin of the anus and pulling and snipping
it , imitating operation for piles, but with no result. The abdomen was then o p e n e d , a n d
a
piece of intestine pulled out an d l i ga t ur e d ; a bl ow wa s s t r uc k upon t he t e s t i c l e s a s t he a ni ma l
was coming round, but the effects were not so marked as would have been imagined. As to
position, when the animal was put-upright there was a distinct fall in blood-pressure, which
became normal when the horizontal posture w a s r e s u m e d ; e l e v a t i o n
o f t h e l e g s w a s f o u n d
t o
raise the pressure. w ith the animal in the upright position, striking the abdomen or extract-