252 
DR. A. D. WALLER AND MR. E. W. REID ON THE 
Table I.—Abstract of Galvanometer Experiments—(continued). 
Experi¬ 
ment. 
Date. 
Animal. 
P.M. 
Spon¬ 
taneous 
beats. 
Apex 
excitation. 
Base Demarca- 
excitation. tion. 
Time p.m. of 
registered 
demarcation. ■ 
1886 
12 
Jan. 2 . 
Cat . 
30' 
S & SN 
NS & N 
SN & S N ? 
11 
11 * • 
Later 
NS 
NS 
SN 
18 
Jan. 4 . 
Cat . . 
30' 
irS & S 
NS 
S 
14 
Jan. 5 
Cat . 
5'-30' 
S 
NS 
s 
11 
1i 
1 hr. 
S 
SN 
15 
Jan. 6 . 
Cat . . 
s 
NS 
sS 
16 
•Ian. 6 . 
Cat . 
s 
NS 
17 
Jan. 7 
Cat . . 
NS 
S I N 
as regards 
Experiment 12.—The observations within an hour after excision were very uniform 
excitatory effects, viz., diphasic variations according to the point of excitation; in the second half of the 
first hour we noticed that, whereas a stronger stimulus was still capable of giving typical diphasic varia¬ 
tions, viz., NS by excitation at A, SN by excitation at B, a weaker stimulus gave only a single variation, 
viz., N by excitation at A, S by excitation at B. Presumably, the excitability was not far removed from 
uniformity, and with this agrees the fact that the two contacts were practically iso-electric. The 
spontaneous beats indicated the passage of an excitatory change from B to A. 
Later, in the second half-hour, the excitatory effects continued uniform, viz., NS by excitation at A, 
SN by excitation at B; the noteworthy point during this period was the appearance of spontaneous 
variations NS ; these were not properly spontaneous, but consequent upon excitation, each stimulus at A 
giving not merely one variation NS, bub a series of two, three, or more such variations at intervals. 
Experiment 13.—This agrees with the supposition that the apex is more injured than the base: we 
omitted to take the demarcation current. 
Experiment 14.—The above remark applies to this experiment during the first half-hour. 
Experiment 15.—Our results are compatible with the supposition that A is warmer than B, and that 
the excitatory variation at B appeal’s twice. 
Our attempt to reproduce the effect by warming B or cooling A failed. 
Experiment 16.—We tried on this heart the effects of thermal injury, bringing a heated point near 
the apex; it gave a variation S, viz., apex positive; thermal injury near the base gave an N variation, 
i.e., base positive; these anomalous results we afterwards found to be due to thermoelectric currents. 
Experiment 17. 
Cat’s heart .— Galvanometer observations begin 25' post mortem. Apex to N screw of galvanometer. 
I. Electrodes on left ventricle. 
Apex excitation 
Base „ 
Apex „ 
Base ,, 
Wealt apex excitation 
Apex excitation 
Bight ventricle excitation 
Base excitation 
Base ,, 
Apex „ 
Base ,, 
Weak hase excitation 
Strong base ,, 
Apex excitation 
Both auricles excited. 
II. Electrodes on right ventricle 
Apex excitation 
Base „ 
Apex ,, 
Base ,, 
Demarcation current N 
NS 
S 
NS 
S 
N 
NS 
SNS 
SNS 
NS 
SNS 
S 
SNS 
NS 
followed by delirium, 
only. 
no effect. 
no effect. 
N 
SN 
NS 
SN 
followed by delirium. 
