ON THE HEART OF THE DOG. 
143 
I. 
The maximum quantity of hloocl which can be thrown out from the left ventricle at a 
single systole. 
Our method of working in determining this quantity was as follows :—After the 
animal had been placed safely in the warm case, and all the connexions had been 
made, an observation was immediately taken in the way described, at a venous 
pressure of 10 centims. ; the pressure was then raised 5 or 10 centims. and another 
observation taken, and so on, until a limit was reached, that is, a point beyond which 
increase of venous pressure did not cause an increased outflow from the aorta. The 
venous pressure was then brought back to 10 centims., and an observation taken as a 
control experiment to determine whether or not the condition of the lungs in the 
meantime had been such as to interfere with the passage of blood to the left auricle. 
Below is given a table showing the results of six experiments upon this point ; the 
complete records of these experiments will be found farther on under Section TIL, with 
the exception of those of May 9 th and May 30tb. The control observation in all the 
experiments, with the exception of the two just named, in which it was not made, 
showed that the passage through the lungs had not yet become seriously obstructed. 
This part of the experiment, indeed, was generally completed within a few minutes, 
and before the lungs had become noticeably oedematous. The temperatures given are 
those of the blood flowing into the right side of the heart. 
The weight of the heart is given together with that of the whole animal, though 
there does not appear to be any constant relationship between it and the weight of 
blood pumped out of the ventricle at each systole. In weighing the heart the vessels 
springing from it were cut off at their origin, superfluous fat removed, and the cavities 
of the heart cut open and cleaned. 
Table showing the maximum quantity of blood which can be thrown out from the 
left ventricle at a single systole. 
No. of 
experiment. 
Date. 
1882. 
Weight 
of Dog. 
Weight 
of heart. 
Temperature 
of blood 
flowing into 
the heart, C. 
Heart 
beats in 
30 
seconds. 
Venous 
pressure in 
centims. 
of blood. 
Arterial 
pressure in 
millims. of 
mercury. 
Total 
outflow 
from the 
aorta in 
30 seconds 
in cub. 
centims. 
Outflow 
from the 
aorta at 
each 
systole 
in cub. 
centims. 
1 
April 4 
grms. 
5891 
grms. 
51*5 
0 
36 
99-5 
36"8 
109 
576 
5-79 
2 
„ 13 
8125 
92 
34-25 
86-5 
50 
135 
750 
8-67 
3 
5J ?! 
35-25 
84 
58 
134 
715 
8-51 
4 
„ 18 
7725 
63 
37 
103 
70 
143 
850 
8-25 
5 
May 2 
8610 
76 
35"5 
89-5 
60 
138 
982 
10-97 
6 
„ 9 
5645 
73 
35 
82-5 
35 
112 
490 
5-94 
7 
„ 30 
9555 
81-5 
37 
102 
59 
121 
950 
9-31 
