The presence of formic and acetic acid supplies the blood with fresh electricity to stimulate the nerves. "Under normal conditions," says Julius Hensel, "this function is assigned to the spleen. This organ takes the part of a rejuvenating influence in the body in the manner of a relay station, and does so by virtue of an invisible but significant device. In every other region of the body the hairlike terminals of the arteries which branch out from the heart merge directly in the tiny tubes (capillaries) of the veins, which lead back to the heart again: in the spleen this is not the case. Here rather the arteries end suddenly when they have diminished to a diameter of one one-hundred-and-fortieth of an inch and end in a bulb (the Malpighian bodies). Under such circumstances the sudden stoppage, particularly the impact of the magnetic blood stream against the membrane of a Malpighian body, exemplifies the physical law of the induction of electricity, in accordance with which the blood that enters the spleen is changed into plasma and exudes through the membrane of the Malpighian bodies. The event indicates some fluidity of the red blood cells, which is a change effected in the body by the impact of electric sparks, and one which electrical therapy also brings about locally to prevent increase in the solid constituents of the blood."
The numerous Malpighian bodies in the spleen act as so many electrical conductors, and the product of their electrical activity is found in the formic and acetic acid of the fluid plasma which filters through the Malpighian corpuscles and supplies the acid tissue of the spleen (pulpa splenica). These acids are the electrolytic division products of lecithin. In the splenic pulp arise the capillaries of the splenic veins whose acid blood is carried directly to the liver, where certain cells formed like galvanic elements possess the property, through the electrical action of formic and acetic acid, of extracting from blood albumen the opposite of acids, namely, alkaline bile. The normal functioning of the liver, therefore, is dependent upon that of the spleen, and since the bile produced by the liver goes to aid the digestive activity of the duodenum, disturbance of digestion must result when the quality of the bile is inferior.