The simple tincture makes a good emulsion with a little mucilage, and the compound tincture may be emulsified with yolk of egg or mucilage, the yolk of egg giving a more stable emulsion.

Cod-liver Oil is frequently prescribed with syrups, e.g.:

As soon as the syrup is added to the emulsion of No. I. complete separation results; it is, in fact, a mistake to attempt to emulsify such mixtures, because a brisk shake mixes a syrup and an oil sufficiently to enable a dose to be poured out. In the case of No. II. the iodine was dissolved in a little ether and added to the oil before the Easton's syrup. Cod-liver oil is not at all difficult to emulsify, but, like other things emulsified, it cannot bear being overloaded with acids. The following recipes (from 'Pharmaceutical Formulas') typify the methods followed in compounding the oil into emulsion:

With Acacia

Mix the oils in a mortar with the gum, add 2 ounces of water and the elixir, and triturate briskly but lightly until an emulsion is formed; then add the rest of the water in portions with diligent stirring.

Some prefer to make the gum into a mucilage with 2 ounces of water, and gradually add the oil to it, with trituration. It is a distinct advantage to use I ounce of lime-water in this formula; it greatly assists emulsification- indeed, a good emulsion results from shaking together equal parts of oil and lime-water.

With Egg

Measure 4 ounces of the distilled water, place the tragacanth in a dry mortar, and triturate with a little of the cod-liver oil; then add the yolk of egg and stir briskly, adding water as the mixture thickens. When of a suitable consistence, add the remainder of the oil and water alternately, with constant stirring, avoiding frothing. Transfer to a pint bottle, add the elixir of saccharin, tincture of benzoin, spirit of chloroform, and oils, previously mixed ; shake well, and add distilled water, if necessary, to make 12 ounces.

A tragacanth emulsion has already been given (page 316).