Digestion is the solution of the food in the stomach for purposes of nutrition. Nitrogenous materials, egg, meat, muscle are digested principally in the stomach, but not entirely so, because the particles of albuminous food which pass from the stomach into the upper portion of the small intestine come into contact with the pancreatic fluid, which is the digestive agent for fats and starches, but which possesses also powerful digestive properties for nitrogenous or albuminous substances and even in a greater degree than the gastric juice of the stomach, which has a strong acid reaction, while the pancreatic juice has an alkali reaction; here is a very interesting illustration how similar digestive processes are accomplished under opposite chemical conditions. The intelligent reader must not fail to observe, from what has been said, that there are two distinctly different digestive processes, namely one going on in the stomach and another equally as important taking place in the small intestines. Pepsin is the active principle of the gastric juice, held in solution in a clear colorless liquid, principally water; it has a sour taste and a peculiar characteristic sour smell. The length of time required by the gastric fluid to dissolve the food depends greatly upon the minuteness of the division of the solid substances to be acted upon, as well as upon the quantity and quality of the peptic fluid. The pepsin changes the physical properties of nitrogenous substances so as to make them soluble in water in any proportion and when the albuminoids have acquired this property they are termed peptones; peptones are simply nitrogenous food which has been modified to fit it for absorption and nutrition of the body.