12

Marshall⁶ that the precipitate of Quinine glycocholate which is obtained by
adding a solution of Quinine to bile, although very insoluble, is easily decom-
posed by carbonic acid and alkaline carbonates, and under ordinary circum-
stances probably plays little part in the absorption of Quinine.

     The solubility of crystalline Quinine alkaloid in fresh ox bile was deter-
mined by me in the following manner:—

       With 15 cubic centimetres of fresh ox bile (the re-action of which tested
            with red litmus paper, was faintly alkaline) .2 gramme crystalline
            Quinine alkaloid was shaken up in a flask. To ensure small division
            of the Quinine the alkaloid was first triturated in a test-tube with a
            little of the bile by means of a glass rod. The flask after being well
            shaken was incubated at 37°C. for three hours, and shaken frequently
            during this period. The flask and its contents were then cooled at
            laboratory temperature (12°C.). The contents of the flask were fil-
            tered through cotton wool with the aid of a water-suction pump, the
            residue on the cotton wool being washed with a small amount of cold
            water and the washings added to the filtrate. The clear filtrate was
            made distinctly alkaline with liquor potassæ. The resulting suspen-
            sion was shaken up three times with ethyl æther. The æther extract
            was filtered and the æther evaporated from the filtrate in a stream of
            hot air (80°C.). The residue was dissolved in 96 per cent. alcohol and
            this solution filtered. The filtrate and washings were evaporated to
            dryness on a water-bath. The residue was then dissolved in weak
            sulphuric acid and the resulting solution filtered, the filter being
            washed with a little of the sulphuric acid. The filtrate and washings
            were made distinctly alkaline with liquor potassæ and the resulting
            emulsion thrice shaken up with æther. The æther extract was fil-
            tered into a weighed porcelain capsule and the æther evaporated in a
            stream of hot air (80°C). The extract was then further dried at 120°C.
            and weighed—with the following results:—

                         Capsule + dried extract=12.065 gm.
                                      Capsule= 11.996 ”

                                                    dried extract= 0.069 gm. (anhydrous Quinine base).

     As crystalline Quinine alkaloid contains 85.7 per cent. anhydrous Quinine
base, .069 gramme anhydrous Quinine base corresponds with .082 gramme
crystalline Quinine, alkaloid. Therefore, 15 cubic centimetres of ox bile
dissolved .082 gramme crystalline Quinine alkaloid; i.e., 15,000 cubic centi-
metres of ox bile can dissolve 82 grammes of crystalline Quinine alkaloid; i.e.,