ACTION OF THE EXCISED MAMMALIAN HEART. 
255 
Table I.—Abstract of Galvanometer Experiments—(continued). 
Experi¬ 
ment. 
Date. 
A nimal. 
P.M. 
Spon¬ 
taneous 
beats. 
Apex 
excitation. 
Base 
excitation. 
Demarca¬ 
tion. 
Time p.m. of 
registered 
demarcation. 
1886 
37 
March 1 
Rabbit . 
N 
s 
N -0112 
14' 
38 
March 2 
Rat . 
N 
s 
N -006 
39 
March 8 
Kitten . 
, . 
N 
s 
S 
40 
March 8 
Kitten . 
s 
NS 
SN 
41 
March 8 
Kitten . 
NS 
NS 
S & ShS 
N 
42 
March 15 
Dog . . 
N 
NS 
S 
S 
43 
March 20 
Dog . . 
NS 
S 
S 
44 
March 26 
Rabbit . 
S 
NS 
S 
45 
March 27 
Cat. 
46 
June 6 . 
Dog . . 
s 
NS 
SN 
N 
Experiment 44 furnished us with good data for the comparison of galvanometric with electrometric 
indications. The electromotive change accompanying the spontaneous beats was galvanometrically S, 
electrometrically NS; the latter we take to be the correct expression of the actual change: it proves 
beyond a doubt that the excitatory change (negativity) manifested itself at apex, and then at base. 
When we shifted the electrode B to the auricle, which was giving two, three, or four beats to one ventri¬ 
cular beat, the electrometer showed a small South variation, corresponding to each beat of the auricle 
alone, followed by a larger double variation North-South with each ventricular beat. On moving electrode 
B to its original position at the base of the ventricle, the auricular beats ceased to affect the electrometer. 
The result obtained above we regard as most significant: it shows auricular negativity, followed by a 
biphasic ventricular negativity, at apex first, then at base; and it proves beyond doubt that the trans¬ 
mission of the excitatory state takes place, otherwise than in the Frog’s heart, probably by nervous 
channels. If the excitatory state had passed from auricle to adjacent part of the ventricle, and thence to 
the apex by muscular continuity, its E.M. expression would necessarily have been a diphasic variation 
South-North. 
Experiment 45.—The spontaneous variation immediately after excision was South , i.e., base negative ; 
the excited variation was North-South with excitation of apex, South-North with excitation of base. 
