have signalled any danger some seconds later. There can be little doubt but that the pulse in
such a case, where the patient was quiet and breathing tranquilly, would have exhibited some
decided alteration had it been observed.
In the second portion of the report it is shown that the essential action of chloroform on
the system is to cause a fall in the mean blood-pressure. This fall is proportionate to the amount
of chloroform inhaled and absorbed into the system. [It would have been interesting to have
known the relation, if any, the condition of the blood-pressure bore to the state of anæsthesia.]
This fall in blood-pressure bears some relation to the respiration, but what this relation
is, is not distinctly stated, and the cause of the fall in pressure is also not clearly assigned, except
(Sec. 19) that it is not due to the direct action of chloroform on the heart, and must be due to
paralysis of the vaso motor centre. This is important when taken in conjunction with the fol--
lowing parts of the report (Sec.3): ". . . If the chloroform is pushed further, there
comes a point not easy to define when the blood-pressure and respiration will no longer be
restored spontaneously, although the heart continues to beat after the inhalation has stopped."
A n d a l s o ( S e c . 2 5 ) : " . . . I t i s n e v e r i n a n y c a s e c e r t a i n t h a t a r t i f i c i a l r e s p i r a t i o n w i l l
restore the natural respiration and blood-pressure, no matter how soon it is commenced a f t e r t h e
respiration stops."
This exposes a comparatively new and insidious danger in chloroform administration, and
o n e a s d i f f i c u l t t o t r e a t a s t h e o l d c a r d i a c s y n c o p e . I t i s q u i t e c o n c e i v a b l e t h a t u n d e r c e r t a i n
circumstances the dose necessary irretrievably to damage the vaso motor centre may be inhaled
with extreme rapidity, and that while the respiration and pulse are still present, the centre may
be almost paralysed before much warning has been given.
From a record of fatal cases in man, it appears possible that this paralysis may, in certain
conditions, be effected almost instantaneously, and before complete insensibility has been
produced.
In Section 20 injection of chloroform into the jugular vein caused no paralysis of the heart.
It should be noted that this is not the most direct channel by which the heart can be reached;
and the experiment, when compared with inhalation, is open to criticism. Chloroform in-
jected into the jugular vein passes with the venous blood to the right auricle, where it is mixed
with the blood of the inferior vena cava from the liver; from the right side of the heart it
passes to the lungs, where the chloroform, being volatile, and the air in the alveoli of the lungs
free from chloroform, a good deal may be lost; finally, what remains of it reaches the heart.
Chloroform given by inhalation is much more likely to reach the heart directly in large
doses passing into the air cells; about one-fifth of the whole blood of the body is at once
e x p o s e d t o i t . T h i s b l o o d , s a t u r a t e d w i t h c h l o r o f o r m a n d u n m i x e d w i t h a n y n o n - c h l o r o f o r m e d
blood, goes direct into the left auricle and ventricle, and by the coronary arteries is first distri-
-buted into the very substance of the heart itself. As Dr. Snow puts it: "In inhalation the
heart is always a little in advance of the rest of the body as regards the amount of chloroform