44 
Table V.- — Determination of the systolic stoppage of the heart of Rana pipiens in one 
hour — Drug injected into abdominal lymph sac. The doses given are in cubic centi- 
meters per gram body weight — Continued. 
MERRELL. 
H. B. AND W. 
Number of animals used. Dose. 
Result. 
Number of animals used. 
Dose. | 
Result. 
9 
[ C. C. 
0. 022 
2 
c. c. 
0.022 
.023 
2 
023 
1 
1 . 
023 
+ 
2 
.024 
2 
024 
2 
.025 
-F 
3 . 
.024 
+ 
1 . 
.026 
5 . 
; .025 
+ 
2 . 
.026 
-F 
l. 
.020 
+ 
1 
.027 
N., B. AND CO. 
P., D. AND CO. 
1 . 
0. 018 

i. 
: o. 020 
_ 
1 . 
.019 
2 
021 
1 . 
.020 
1. 
021 
+ 
2 
.020 
-F 
1 . 
022 
+ 
2 
.021 
1 . 
.023 
+ 
3 
.021 
-F 
1 . 
i .025 
+ 
3 . 
.022 : 
-F 
SUMMARY. 
Preparation. 
Dose. 
Mulford No. 1 
c. c. mgm. 
0 . 012 = 1.2 
. 016 = 1.6 
. 020 = 2.0 
. 021 = 2. 1 
. 022 = 2.2 
. 024 = 2.4 
. 025 = 2. 5 
. 027 = 2.7 
. 030 = 3.0 
. 040 = 4.0 
Mulford No. 2 mWHWWW 
B. W. and Co 
P., D. and Co 
N., B. and Co 
Merrell . 
H. B. and W 
S. and D 
Lloyd Bros 
Digitalone No. 3 
Digitalone No. 2 
“Focke” method . — The second method upon the frog’s heart which 
we employed was that of Focke, modified, however, in one or two 
important particulars. In the first place, we pithed all the frogs, 
while Focke does not do this until the experiment is over. It is 
absolutely essential that this should be done for purely humanitarian 
reasons, and if this operation interferes with the accuracy of his 
method then the method can not be used. As a matter of fact, this 
was done very carefully so as not to lose any blood, and the piece of 
sharpened wood was left in the brain cavity so as to prevent hem- 
orrhage. The other modification was patterned after Wang, who 
found it was hard to determine when the ventricle may be said to 
have come to a permanent systolic standstill. We found exactly the 
same difficulty, and so adopted Wang’s modification of watching for 
the stoppage of the circulation. Wang does not mention how he 
determines this, but the method we used was to watch with the 
microscope the stoppage of the circulation in the web of the foot. 
This itself is not always satisfactory, because in some animals, due to 
