After the food has been acted upon by the gastric juice in the stomach, and the albuminoids have been in a great measure rendered soluble and absorbed, the acid chyme passes into the duodenum, where it is acted upon by the bile and the pancreatic juice, both of which are alkaline. The role of the bile is to emulsify the fats, and of the pancreatic juice to turn the starch into glucose. The bile is secreted by the liver, and it is rightly thought that the liver plays a large part in causing indigestion. If the bile is deficient there is constipation and often distressing flatulence; if it is secreted in excess the bile salts are not re-absorbed, but circulate in the blood, producing great depression of spirits. The bile may also regurgitate into the stomach, causing vomiting of a very acrid substance. If the pancreas fails to fulfil its part, the starchy foods are not converted into glucose, the process of digestion is not completed, and undigested food passing down the alimentary canal causes irritation and diarrhoea, and the patient emaciates.