Prep. Ox gall is placed in Appendix A , and from it the purified bile is ordered to be made, by mixing the fresh gall with twice its volume of rectified spirit, and after twelve hours, when the sediment has subsided, evaporating the decanted liquid over a water bath until it has acquired the consistence of a vegetable extract. By this process the mucus which is always present in bile is separated by the action of the spirit, and the preparation is thus rendered much less prone to putrefaction.

Prop. & Comp. Purified bile occurs as a yellowish green substance, somewhat firm and adhesive, having a faint and peculiar odour, and a taste at first very sweet, but soon becoming intensely bitter; it is soluble both in water and spirit. Bile, when separated from the mucus of the gall bladder, consists of two distinct portions, the true biliary substance and the colouring and fatty matters. The former, a species of soap, is of a pale yellow colour, and is composed of two salts, glyco-cholate and tauro-cholate of soda. Glyco-cholic acid (HO, C52 H42 No11), when pure, can be crystallized in white acicular needles, as likewise can some of its salts. Tauro-cholic acid (HO, C32 H44 No13 S2), the least abundant acid in ox bile, has not yet been obtained in a crystallized state.

The green colouring matter somewhat resembles the cliloro-phylle of plants. The peculiar fat of bile is cholesterine (C52 H44 O2) which readily crystallizes and forms the chief constituent of gall stones.

When bile has been purified by the above-mentioned process, its watery solution is not precipitated on the addition of rectified spirit. A grain or two of bile in 1 fl. drm of water, when treated with a drop of fresh syrup, and then a little sulphuric acid, cautiously added, exhibits a play of colours from red to violet.

Therapeutics. Dried bile appears to act as a slight laxative on the alimentary canal when given in the ordinary medicinal doses; its use is supposed to be indicated in cases attended with deficient excretion of biliary matter, as shown by the pale colour of the alvine evacuations. It has also been said to be useful as a stomachic in some forms of functional dyspepsia, especially in cases where vomiting occurs after food. More clinical knowledge of its efficacy as a remedy is required before its value can be said to be fairly established.

Dose. Of purified bile, 5 gr. to 10 gr., or more, formed into pills, or given in small gelatinous capsules. When the object is to affect the intestines rather than the stomach, the latter mode is preferable.