586 
The Stomach and Intestines a Respiratory Surface, 
BEING THE CAUSE OF THE BLOOD’S CIRCULATION THROUGH 
the Liver. 
By Charles Searle, M.D., Bath. 
[From the Lancet.] 
The powers for circulating the blood through the system are 
now, I believe, pretty generally acknowledged to reside in the 
heart, in its twofold capacity of a forcing and a sucking pump, and 
in the action of the capillary vessels. The left ventricle propelling 
the blood through the arteries by its contraction, and the auricle 
by its dilatation (and the partial vacuum formed by the expansion 
of the chest, and the atmospheric pressure ab externo), aids it in 
its return by the veins, into which it is first conveyed by the ex- 
citement imparted by the arterial blood to the capillaries, I say, 
by the stimulus of the arterial blood in the capillary vessels ; for 
these are found to accord in action with the respiratory function, 
capillary excitement being the result of chemical action, developed 
by the agency of oxygen in its combination with the elements of 
the blood. 
Such being the circulating powers, it has ever been a matter of 
astonishment with me how the blood could be circulated through 
the liver, seeing that these powers are wholly inoperative with 
respect to the liver, or nearly so. Light is at length, I am of opi- 
nion, thrown upon this matter. I believe I can now see clearly 
what heretofore has been a matter of so much doubt and difficulty 
to me ; and this I now beg leave to submit to the notice of the pro- 
fession. The action of the heart, I repeat, must be wholly inope- 
rative, or nearly so, in the blood’s circulation through the liver; 
and the blood furnished to the liver being at the same time venous, 
the united streams brought by the veins of the stomach, bowels, 
spleen, and pancreas, and associated in the portal vein, must be 
equally inoperative as regards the capillary vessels. Well, how 
then is the circulation (through the liver) effected 1 Simply by 
the surface of the stomach and bowels being a respiratory surface, 
and thus imparting (by the oxygen absorbed) the vital qualifica- 
tions necessary for the blood proceeding to the liver ; but first cir- 
culating on their surfaces, and to the alimentary juices also ab- 
sorbed from these surfaces. The alimentary material, moreover, 
in its passage to the stomach, being first masticated, is mixed with 
the air of the mouth : air, too, being constantly swallowed with 
the saliva, is received into the stomach, in combination, also, with 
