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before. As far as I am aware there is no text-book on surgery of the present day, except
Sir Joseph Lister's article in "Holmes's Surgery," that does not recommend that the pulse
as well as the respiration should be watched for signs of the effect of chloroform, and it is new
to prove, as the Hyderabad Commission has proved, that to watch the pulse at all is both wrong
and dangerous.
The photograph of two original tracings of Experiment No.186 which accompanies this
paper demonstrates the futility of attention to the pulse in chloroform administration. For
example, in Tracing III., Ludwig, though the pulse of the dog experimented on was appa
- r e n t l y m u c h b e t t e r a t 2 h o u r s 5 5 m i n u t e s t h a n a t 2 h o u r s 5 4 m i n u t e s , i t w a s n o t r e a l l y s o .
Dr. Gaskell has shown that when the blood-pressure is high the pulse must necessarily be
better than when the blood-pressure is low. The pressure at 2 hours 54 minutes was much
higher than at 2 hours 55 minutes, and the pulse was therefore in reality better in proportion,
though it was smaller in the tracing.* On the other hand, the danger of waiting for signs in
the pulse of failure of the heart under chloroform is well shown in the Tracing IV., Ludwig,
at the end of which the failure of the pulse at 3 hours 19 minutes 15 seconds, was a sign of
impending death.
The two tracings demonstrate all that it is possible to know regarding the safe adminis-
- t r a t i o n o f c h l o r o f o r m , a n d a r e w e l l w o r t h c a r e f u l e x a m i n a t i o n . ( E v e r y t h i n g w h i c h o c c u r r e d i n
the experiments was marked and recorded on the tracings as the drum revolved, and nothing
except what is written in red ink† Was added afterwards.) The most remarkable points they
exhibit are ( a) the uniformly gradual and regular fall of blood-pressure which occurs when
chloroform is administered in such a way that the breathing is perfectly regular, and (b) the
entire absence of danger if the administration is stopped when the animal or patient is "under".
Formerly we were told that chloroform lowers the blood-pressure; that this in itself shows that
its administration is dangerous; and that occasionally the fall is so unexpected and capricious
as to produce sudden death by stoppage of the heart. The Hyderabad Commission has shown
(1) that the lowering of the blood-pressure, which chloroform and all anæsthetics cause when
efficiently administered, is in itself a harmless event, if the respiration alone be attended to and
taken as a guide, and if the administration be stopped when the patient is fully anæsthetised;
and (2) that the sudden falls of pressure which the Glasgow Committee asserted are dangerous,
and attributed to chloroform, are due to stimulation of the vagus, and, by slowing the circula
-tion, are a safeguard against overdosing. The Hyderabad Commission has further proved that
all irregularities in the fall of the blood-pressure and in the circulation under chloroform, in-
-cluding such an irregularity as dilatation of the heart, which never occurs when chloroform is
administered properly, are due to improper administration, with irregular breathing and in-
-sufficient air.
There is no loophole of escape for the opponents of principles which Syme long ago
showed to be essential for safety in the administration of chloroform. Tracings 3 and 4 of Ex--
periment No. 186 of March 6th, 1890, were not produced accidentally, but are examples of what
[* This statement is open to correction.] † Black in the diagram.