675. Such appear to be the real purposes accomplished by the bile in the process of digestion. Several uses have been assigned to it, in promoting this process, which it does not serve. Seeing the instantaneous change wrought in the chyme on its contact with the bile, it was reasonable to suppose that the main use of the bile was to convert chyme into chyle, a purpose apparently of sufficient importance to account for the immense size of the gland constructed for its elaboration. The soundness of this conclusion appeared to be established by direct experiment. Mr. Brodie placed a ligature around the choledoch duct of an animal: after the operation the animal ate as usual: on killing the animal some time after it had taken a meal, and examining the body immediately after death, it was clear that chymification had gone on in the stomach just as when the choledoch duct was sound, but no chyle appeared to be contained either in the intestines or in the lacteals. In the lacteals there was found only a transparent fluid, which was supposed to consist of lymph and of the watery portion of the chyme. Mr. Brodie’s experiments seemed to be confirmed by those of Mr. Mayo, who arrived at the conclusion, that when the choledoch duct is tied, and the animal is examined at various intervals after eating, no trace whatever of chyle is discoverable in the lacteal vessels. But these experimentalists inferred that no chyle existed in the intestines or lacteals, because there was present no fluid of a milk-white colour, a colour not essential to chyle, but dependent on the accident of oily or fatty matter having formed a portion of the food. These experiments have been repeated in Germany by Tiedemann and Gmelin, and in France by Leuret and Lassaigne, who have invariably found, after tying the choledoch duct, nearly the same chylous principles, with the exception of those derived from the bile, as in animals perfectly sound; and the English physiologists have since admitted that their German and French colaborateurs have arrived at conclusions more correct than their own.