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(ii) the explanation of the sudden effect on the heart sometimes occurring under the influence
of chloroform, and observed equally by the Hyderabad Commission and by us, but ascribed by
the Commission to asphyxia and by us to a peculiar, and apparently capricious, influence of
chloroform.
(i) In the report of the Hyderabad Commission it is stated that chloroform "causes a
gradual fall in the mean blood-pressure . . . . . As this fall continues the animal first
becomes insensible, then the respiration gradually ceases, and, lastly, the heart stops." This
is regarded as the normal course of events, and in confirmation of it reference is made to Ex-
periments 168, 169. and 170. We have carefully examined these tracings, and others of a
similar character. Like our own tracings, they show that, under the administration of chloro-
form, the blood-pressure is continually lowered. and that when chloroform is pushed the depres-
sion is apt to assume what the Hyderabad Commission admit to be a "dangerous" degree.
These tracings seem to us in themselves to show that chloroform when pushed has a disastrous
effect on the heart as well as on the respiration.
In most of the experiments two different kinds of tracings were taken,—one by Ludwig's
and another by Fick's apparatus. The Ludwig curve shows more particularly the blood-pres
- s u r e , w h i l e t h e F i c k t r a c i n g , t a k e n w h i l e t h e L u d w i g t r a c i n g i s s u s p e n d e d , s h o w s s p e c i a l l y t h e
excursions produced by the individual pulsations of the heart. What we notice, specially in
169 and 170. is that there is a gradual fall of the blood-pressure, occupying four minutes in
the one case and five and a-half in the other. Fick tracings, taken at intervals, show not only a
reduction of pressure, but a very striking diminution in the force of the pulsations. By the
time the breathing stops the pressure is reduced almost to zero, and the Fick tracings, taken
immediately after the cessation of the breathing, show the merest indication of movements in
the heart, whose pulsations are reduced in number to less than half. So far as the efficiency
of the heart is concerned in carrying on the circulation, it has virtually ceased to act by the
time the respiration has stopped, and we are inclined to believe that the inefficiency of the
circulation may be. at least in part, the cause of the cessation of the respiraton; this opinion
being based on the fact that the fall in blood-pressure is so extreme before the respiration stops
as to interfere with the proper nutrition of the respiratory centres.
(ii) In paragraph 30. section (8) of the Hyderabad Report it is said that "the effect of
involuntarily holding the breath . . . . is much more remarkable, the pressure often fall-
ing with great suddenness while the heart's action is markedly slowed." Further on, in Section
( 12) t hey say: "Compl et e, or al most compl et e, asphyxi a, as by f or ci bl y cl osi ng t he nose and mout h
or closing the tracheal tube after tracheotomy, has an effect similar to but more marked than
that produced by holding the breath, and the character of the tracing corresponds precisely
to that produced by irritation of the peripheral end of the cut vagus. The pressure falls ex--
tremely rapidly, sometimes almost to zero, and the heart's action becomes excessively slow, or
even stops for a few seconds. If the Fick trace of Experiment 148 be compared with the
photographic reproduction of Trace A of the Glasgow Committee it will be seen that they are
Committee attributed to some capricious action of chloroform upon the heart, was undoubtedly