Techniques: Maceration

January 14th, 2008

Maceration is another process that is frequently required to be performed in making up medicines, and consists simply in immersing the medicines in cold water or spirits for a certain time.

Source: Enquire Within Upon Everything.

Techniques: Sifting

January 13th, 2008

Sifting is frequently required for powdered substances, and this is usually done by employing a fine sieve, or tying the powder up in a piece of muslin, and striking it against the left hand over a piece of paper.

Source: Enquire Within Upon Everything.

Techniques: Filtering

January 11th, 2008

Filtering is frequently required for the purpose of obtaining clear fluids, such as infusions, eye-washes, and other medicines; and it is, therefore, highly important to know how to perform this simple operation. First of all take a square piece of white blotting paper, and double it over so as to form an angular cup. Open out this filter paper very carefully, and having placed it in a funnel, moisten it with a little water. Then place the funnel in the neck of the bottle, and pour the liquid gently down the side of the paper, otherwise the fluid is apt to burst the paper.

Source: Enquire Within Upon Everything.

Techniques: To Powder Substances

January 9th, 2008

Place the substance in the mortar, and strike it gently with direct perpendicular blows of the pestle, until it separates into several pieces, then remove all but a small portion, which bruise gently at first, and rub the pestle round and round the mortar, observing that the circles described by the pestle should gradually decrease in diameter, and then increase again, because by this means every part of the powder is subjected to the process of pulverization.

Some substances require to be prepared in a particular manner before they can be powdered, or to be assisted by adding some other body. For example, camphor powders more easily when a few drops of spirits of wine are added to it; mace, nutmeg and such oily aromatic substances are better for the addition of a little white sugar; resins and gum-resins should be powdered in a cold place, and if they are intended to be dissolved, a little fine well-washed white sand mixed with them assists the process of powdering. Tough roots, like gentian and calumba, should be cut into thin slices; and fibrous roots like ginger, cut slanting, otherwise the powder will be full of small fibres. Vegetable matter, such as peppermint, loosestrife, senna, &c., requires to be dried before it is powdered.

Be careful not to pound too hard in glass, porcelain or Wedgwoodware mortars; they are intended only for substances that pulverize easily, and for the purpose of mixing or incorporating medicines. Never use acids in a marble mortar, and be sure that you do not powder galls or any other astringent substance in any but a brass mortar.

Source: Enquire Within Upon Everything

Techniques: Decoction

January 1st, 2008

Decoction, or boiling, is employed to extract the mucilaginous or gummy parts of substances, their bitter, astringent or other qualities, and is nothing more than boiling the ingredients in a saucepan with the lid slightly raised. Be sure never to use an iron saucepan for astringent decoctions, such as oak-bark, galls, &c., as they will turn the saucepan black and spoil the decoction. The enamelled saucepans are very useful for decoctions, but an excellent plan is to put the ingredients into a jar and then boil the jar, thus preparing it by a water bath, as it is technically termed; or by using a common pipkin, which answers still better. No decoction should be allowed to boil for more than ten minutes.

Source: Enquire Within Upon Everything.

Techniques: Infusion

January 1st, 2008

Infusion is one of the most frequent operations required in making up medicines, its object being to extract the aromatic and volatile principles of substances, that would be lost by decoction or digestion; and to extract the soluble from the insoluble parts of bodies. Infusions such as calumba and quassia may be made with cold water, in which case they are weaker, but more pleasant. The general method employed consists in slicing, bruising or rasping the ingredients first, then placing them in a common jug (which should be as globular as possible), and pouring boiling water over them. Cover the jug with a cloth folded six or eight times, but if there be a lid to the jug so much the better. When the infusion has stood the time directed, hold a piece of very coarse linen over the spout, and pour the liquid through it into another jug.

Source: Enquire Within Upon Everything.

Techniques: Digestion

January 1st, 2008

Digestion resembles maceration, except that the process is assisted by a gentle heat. The ingredients are placed in a flask, such as salad oil is sold in, which should be fitted with a plug of tow or wood, and have a piece of wire twisted round the neck. The flask is held by means of the wire over the flame of a spirit lamp, or else placed in some sand warmed in an old iron saucepan over the fire, care being taken not to place more of the flask below the sand than the portion occupied by the ingredients.

Source: Enquire Within Upon Everything.