250 
DR. A. D. WALLER AND MR. E. W. REID ON THE 
Table I.—Abstract of Galvanometer Experiments. 
! 
Experi¬ 
ment. 
Date. 
Animal. 
P.M. 
Spon¬ 
taneous 
beats. 
Apex 
excitation. 
Base 
excitation. 
Demarca¬ 
tion. 
Time p.m. of 
registered 
demarcation. 
1885 
1 
Oct. 31 . 
Cat . . 
2 hrs. 15' 
N 
2 
Nov. 30. 
Cat . . 
1 hr. 30' 
N 
N -002 d 
90' 
3 
Dec. 2 . 
Cat . 
1 hr. 15' 
, . 
N 
S 
•0032 d 
53' 
4 
Dec. 3 . 
Cat . . 
45' 
wS 
s 
S 
45' 
5 
Dec. 4 . 
Rabbit . 
1 hr. 15' 
. # 
N -0136 d 
60' 
6 
Dec. 4 . 
Cat. 
7 
Dec. 4 . 
Rabbit. 
8 
Dec. 14 . 
Cat . . 
N 
N 
N 
S 
Remarks to Galvanometer Experiments of Table I. 
Experiment 1.—Oar first observation was made upon tbe heart of a Cat, which had been killed by 
chloroform 2 hrs. 15 mins, previously; we were looking- for the effects of injury upon its E.M.F., and 
observed spontaneous variations similar to the variations which accompany the normal rhythmic beat; 
the heart was motionless during these variations, which were such as to indicate negativity of apex. 
Experiment 3.—This heart showed no spontaneous variations 53 mins, after death; beats had ceased 
to be visible 35 mins, post mortem. Excitation gave rise not merely to a single variation, but to a series 
of variations, indicating negativity of the excited part; we noticed this at the following periods post 
mortem: 1 hr. 18 mins., 1 hr. 53 mins., and 2 hrs. Thermal excitation of apex 2 hrs. 10 mins, post 
mortem gave S variation; at 2 hrs. 13 mins, post mortem excitation at base and apex gave S. 
Experiment 4.—Electrode A was at apex of left ventricle; electrode B was at base of right ventricle. 
Experiment 5.—The demarcation current was such as to indicate negativity at apex; it rapidly 
diminished from the moment when it was made. 
1 hr. 10 mins, post mortem the demarcation current was . . . '005Gr> N 
1 hr. 30 mins, post mortem ,, ,, ... - 0032 d 
Section at apex now caused it to rise to. '0192d 
A few minutes later it stood at.'01S4 d 
And a section at the base reduced it to. - 0128d 
The injury variation was thus considerably greater at apex than at base. 
The excitatory variations were unsatisfactory, showing great want of uniformity, partly due, no donht, 
to shifting of contacts. 
Spontaneous variations were observed l hr. 20 mins, post mortem, there being at this time no trace 
of visible movement of the heart; they were subsequent to thermal excitation. 
Experiment 6.—Cat’s heart. 3 hrs. 21 mins, post mortem. Electrodes applied to base and apex were 
iso-electric; section of apex gave a N deflection of -0036d. The entire heart was in rigor, and we 
could not satisfy ourselves that excitation had any effect. 
Experiment ?.—Rabbit’s heart. 5 hrs. post mortem. The left ventricle was in rigor, the right 
ventricle flaccid; electrodes on middle of right and left ventricle respectively showed no difference of 
potential. 
Apex and base of right ventricle gave a current of - 0011i> N. On left ventricle a current of ’OOOIGd N. 
Section of apex of left ventricle increased this to - 001d N. 
Section of base converted it to - 024d S. 
On the right ventricle section of apex increased current from '001 Id to '016d N. 
Experiment 8.—The demarcation current was such as to indicate negativity of base, viz., S; all 
variations spontaneous, excited from apex, or excited from base, gave a variation in the same sense, 
viz., N, which we could not attribute to shifting of contacts. 
Section at base gave a small S deflection in comparison with a large N deflection caused by section at 
apex. It is allowable to conclude from the original direction of the demarcation current that the base 
was more injured than the apex at the commencement; this is confirmed by the effects of section at the 
two points, the effect being greater at the apex than at the base. 
As regards the excitatory variations, the results are paradoxical, hut intelligible on the supposition 
that the excitatory variation is manifested by the less injured part alone, viz., in this case the apex; and 
upon this supposition it is intelligible that the spontaneous beat should have given a similar variation. 
