The methods of emulsifying the ' balsam' have already been described (page 322, see also page 340). When mucilage and solution of potash are prescribed with it dispensers frequently bungle the emulsion, so that the following example may be noted:

Mix in a mortar 45 grains of powdered acacia gum and copaiba. Separately mix the liq. potassae with 7 drachms of water; of this add 70 minims to the mortar-contents and stir vigorously until the emulsion is quite smooth; then add the rest of the solution gradually, and make up.

Copaiba Resin

Rub the resin with one-third its weight of sugar of milk, and about its own weight of pulv. acaciae, and add the water gradually. Mr. Gerrard recommends the resin to be rubbed with twice its weight of compound powder of almonds until well incorporated, adding the water after the manner of forming an emulsion.

Chloroform is made into an excellent emulsion with tincture of quillaia, thus : Chloroform tincture 3iij., water to

Ext. Filicis Maris. - For each drachm use 2 ounces of new milk. Resin soap or even powdered soap is excellent, e.g.

Rub the soap with the extract, and gradually add the water. The extract also emulsifies with half its weight of powdered acacia gum by the 'English method.'

Iodoform is made into an emulsion (for injection) either with starch mucilage or with pulv. trag. co. Use precipitated iodoform in impalpable powder. Examples:

In this case 40 grains of pulv. trag. co. made the 175 grains of iodoform into an excellent emulsion.

Petroleum is now commonly prescribed as an emulsion. The heavy oil (paraffinum liquidum) is intended, and the unbleached kind or the Russian water-white should be used, otherwise the emulsion will stink in a few days owing to the sulphur compounds in the bleached oil. Emulsify with acacia in the same manner as cod-liver oil. A correspondent of The Chemist and Druggist was called upon to compound an emulsion of ordinary paraffin oil. The following was his method:

Spermaceti may be emulsified with yolk of egg after being very finely powdered with rectified spirit.

Terebene may be emulsified in the same way as turpentine. The following prescription is a fairly difficult one to compound:

Make a mucilage with 4 drachms of acacia and 6 drachms of peppermint-water in a mortar; of this reserve 2 drachms; with the remainder in the mortar rub the terebene until emulsified, and dilute with 2 ounces of peppermint-water. Dilute the reserved 2 drachms of mucilage with peppermint-water; transfer to a bottle, and with this emulsify the tincture of tolu; to this add the terebene emulsion and finally the other ingredients.

Turpentine

Yolk of egg emulsifies turpentine well. Triturate the yolk carefully in a mortar, add gradually twice its volume of water, and strain through muslin. Of this mixture transfer to a bottle a measure equal to, or slightly more than, the turpentine to be emulsified, shake, add the whole of the turpentine, shake until thoroughly emulsified, and dilute further if necessary. Forbes's method for the emulsification of essential oils, such as turpentine, consists in the addition of 20 grains of acacia to each ounce of oil contained in a dry bottle, diffusing by a slight shake, then adding 1/2 ounce of water, and briskly agitating for a few seconds, when the emulsion is complete, and can be diluted by the further addition of water without separation of the oil.