Emulsion

Emulsion is the term applied to those preparations in pharmacy in which oleaginous substances are suspended in water by means of gum, sugar, carrageen, yolk of egg, &c. The production of these emulsions is often not an easy matter, and requires judgment and skill. In general it will be found that the bulk of the emulsifier must first be taken, while the oil should only be added little by little, rubbing together in a mortar, and taking care that it is completely absorbed or emulsified before further additions. Should too much be added, the effect is to throw out most of what has already been incorporated, and it is then almost impossible to remedy the error. The emulsion of cod-liver oil is probably known to all, but there are many emulsions in which solid substances have to be suspended, and to them the directions above given are not always applicable.