It has been known for many years that the gall bladder is capable of concentrating bile salts and pigments by the absorption of water and simple salts. Associated with this process of absorption is a decrease in pH and a fall in the concentration of bicarbonate of gall bladder bile. As early as 1869 Pfliiger noted that the CO, liberated by acid was greater in hepatic than gall bladder bile of the dog. I n 1916 Quagliariello showed that the pH was greater in hepatic than gall bladder bile in the same species. These observations have been extended to a great variety of animals (Okada, '16 ; Drury et al., '24 ; Neilson and Meyer, '21).
The present work is a study of the changes in the ionic composition of gall bladder bile in the guinea pig under varying conditions. An unexpected finding was the observation that bicarbonate was secreted into the lumen of the gall bladder under certain conditions both in vivo and iuz vitro.
METIIODS
Im uivo experiments -Guinea pigs weighing from 500 to 1000 gm were anesthetized with nembutal (25 mg/kgm body weight) injected intraperitoneally. Since anesthesia was relatively light, it was found necessary to infiltrate the abdominal wall with 1% procaine. The abdomen was opened by a midline incision. A small block of wood placed at the mid-portion