ACTION OF THE EXCISED MAMMALIAN HEART. 
253 
Table I.—Abstract of Galvanometer Experiments—(continued). 
1 
Experi 
meat. 
Date. 
Animal. 
P.M. 
Spon¬ 
taneous 
beats. 
Apex 
excitation. 
Base 
excitation. 
Demarca¬ 
tion. 
Time p.m. of 
registered 
demarcation. 
1886 
18 
Jan. 15 . 
Cat . 
s 
S 
s 
N 
| 19 
Jan. 15 . 
Cat . 
SN 
NS & N 
s 
20 
Jan. 13 . 
Dog. . 
2 hrs. 
NS 
N 
s 
N 
120' 
21 
Jan. 22 . 
Cat . . 
5'—15' 
SN 
NS 
SN 
S 
5' 
22 
Jan. 22 . 
Cat . 
8' 
SN 
NS 
SN 
23 
Jan. 27 . 
Dog. . 
10-15' 
NS 
s 
N 
10' 
21 
Jan. 28 . 
Dog. . 
2' 
N 
N 
SN 
25 
Jan. 30 . 
Dog . . 
N 
N 
SN 
26 
Feb. 5 . 
Cat . 
25' 
N 
S 
27 
Feb. 9 . 
Sheep . 
NS 
SN 
N -012 d 
26' 
28 
Feb. 12 . 
Rabbit . 
25' 
S 
NS 
S & SN 
Experiment 17 (continued). 
Spontaneous beat.NS 
Base excitation . SN 
Base „ S 
1 hour post mortem excitatory effects uncertain. 
Injury at base . S 
Injury at apex . N 
Change caused by apex injury less than that caused by base injury. 
Experiment 19.—We noted that 15 mins, post mortem the spontaneous variation was SN, at 34 mins, 
post mortem it was N. 
Experiment 21.—We cooled this heart by placing it in a vessel surrounded by melting ice; in the 
course of cooling we observed the following effects of excitation at A : NS, NSN, N, and nothing. The 
variation N SN is compatible with A cooler than B; the variation N is due to the excitatory process not 
reaching to B. 
Experiment 23.—These effects are compatible with greater injury at apex than at base. We tried the 
effects of excitation with the electrodes on the two borders of the left ventricle, and obtained by excita¬ 
tion near N the variation NS ; near S the variation SN. 
On stimulating midway between N and S, we obtained no appreciable variation. 
On exciting nearer to N, we obtained NS ; on exciting nearer to S, we obtained SN. 
Similar effects were obtained on the right ventricle. 
Spontaneous effects were now observed N, N and S being on apex and base. 
Apex excitation gave N. 
Base excitation gave SN. 
Later (56 mins, post mortem) we observed spontaneous variation SN on the L.Y. 
59 mins, post mortem we observed spontaneous variations on the R.Y., N ; on the L.V., S. 
Experiment 24.—Tested laterally on the L.V., we obtained from excitation near A a variation NS, 
from excitation near B a variation SN. 
With A and B at apex and base of R.Y., we obtained, 2 hours and 20 mins, post mortem, a series of 
spontaneous variations SN. 
Experiment 25.—We took the spontaneous variation leading off from the right and left borders of the 
L.Y., left border to S electrode, right border to N electrode, and observed it to be SN; this variation 
indicates negativity, beginning on the left side, ending on the right side. 
2\ hours post mortem, spontaneous beats NS were still apparent, the R.Y. being led off in the usual 
manner from A and B. 
Experiment 26.—Extreme susceptibility to injury; the slightest touch gave permanent deflections ; the 
current of injury was '014 d. 
Experiment 27.—Tested laterally, A being on the right border and B on the left border of the L.Y., 
we obtained, by excitation near A, NS; by excitation near B, SN; spontaneous variation, S. 
On the R.Y., laterally, we obtained similar effects by excitation near A and B respectively, viz., NS 
from excitation of A; SN from excitation of B. Spontaneous variation was NS, A being on the left 
border, B on the right. 
