Bile is the first digestive agent with which the food comes in contact on leaving the stomach and entering the intestines, and immediately on the acid chyme mixing with the alkaline bile, a white flocculent emulsion is formed, which emulsion has been described by many writers as a precipitation of the albuminose (digested albumen). Later {15} researches by myself and others have, however, shown that it is not the bile which precipitates the albuminose, but the acid of the chyme, which in reality sets free certain ingredients of the alkaline bile. In the majority of cases there is not even a true precipitation, for on throwing the milky-looking mixture upon a filter, I found that almost nothing remained behind, and the filtrate was nearly as white as the original liquid. Further, if the albuminose be separated from the chyme, and the chyme then brought into contact with the bile, the same flocculent-looking milkiness still appears. Nay, more, on adding equal parts of sheep's bile (fresh) to gastric juice drawn from a dog's stomach in full digestion, the apparent flocculent precipitate still appeared, although the acidity of the gastric juice remained unneutralized; and on throwing the whole into a filter, I found that the liquid that drained through was as milky and flocculent-looking as the original. The office of bile in the digestive process is neither to act on the albuminous[5] nor amylaceous portions {16} of our food; its chief action being to assist in the absorption of fats. When bile is mixed with neutral fat, little change is observed, but when brought in contact with the fatty acids, an immediate emulsion takes place. Lenz and Marcet[6] pointed out how the neutral fats of our food are transformed into fatty acids during their sojourn in the stomach; and Bidder and Schmidt[7] illustrated by experiments on dogs the important part played by the bile in their absorption. A dog, which in its normal condition absorbed on an average 7 grains of fat for every 2 pounds of its weight, absorbed only 3, or even as little as 1 grain, after the bile was prevented entering the intestines, in consequence of a ligature being applied to the gall-duct. [Footnote 5: In speaking of the properties of the bile, I may mention that, although bile has no digestive power (properly speaking) over albuminous substances, yet, when injected into the subcutaneous cellular tissue of a healthy animal, it eats its way out through the skin, just as gastric juice or lactic acid does under similar circumstances. Even the muscles with which it comes in contact appear to be eaten away.] [Footnote 6: _Vide_ a Discourse on the Chemistry of Digestion, by Dr. Marcet. Journ. of the Chem. Soc., Oct. 1862.] [Footnote 7: "Die Verdauungssaefte und der Stoffwechsel." Leipzig, 1852.]