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.
One of the substances contained in bile, lecithin, is of wide importance. When it was referred to a moment ago, I spoke only of its individual chemical nature as a fat in combination with ammonium phosphate, as by so doing I avoided error in connection with its apparently complicated formula, which includes glycerophosphoric acid, trimethylamin, palmitic and stearic acids. As it is a fatty substance, the only question that arises, is, what does it contain besides fat? This may be answered by a process of substraction:
2 (C_{21} H_{42} O_{4}) C_{42} H_{84} O_{8} which represents tallow or stearate of glycerine. Lecithin, C_{42} H_{84} O_{9} NP, differs from this only by a larger amount of NP. The significance of this difference becomes clear when two atoms of water are added. Then ammonium phosphate, PO_{3} H_{4}, N is formed. The two atoms of water needed for the condensation of the ammonium phosphate from the stearate are obtained by separating them away from two of glycerine.
The bile contains lecithin in a partially oxidized form. The chemical “remainders” are biliverdin and cholesterin. The latter when normal has, as you know, the power to neutralize snake venoms and other poisons, and thus acts as a natural anti-toxin. In addition, the bile contains combinations of stearine with gelatine and with carbonate and sulphate of sodium, which theoretical chemists believe are twin compounds of glycocholate and taurocholate. These fatty compounds depend upon stearine partly oxidized, that is deprived of a certain number of atoms of hydrogen.