In most of the large pharmacies the duty of preparing infusions for use during the day falls to the assistant who has been on night-duty. The question whether the dispenser is justified in using concentrated infusions or not has been answered with much circumspection by an experienced pharmacist, who said, 'Never use concentrated infusions when time allows of fresh ones being made. The aroma of the recent infusion is often wanting, whilst the difference in appearance is in most cases very marked.'

The British Pharmacopoeia, in order to meet the objection of loss of time, which is frequently urged against fresh infusions, a, Orifice for filling steam-bath b.

Graduated Infusion-Jar.

Infusion-Pot.

A, Pot. b, Strainer to hold the drug.

(Japanese teapots with strainer are serviceable for making infusions.)

German Infusion-Apparatus.

The water boils and the steam (d) keeps the pot (e) hot. reduced the period of infusion so that any medicine containing one can now be dispensed in half an hour.

When 8 ounces of any infusion is required, 10 ounces at least should be made, as the marc absorbs a good deal of the menstruum, and the Pharmacopoeia does not direct it to be pressed out.

In some parts of the country it is quite the exception to use anything except concentrated infusions in dispensing, and this fact is recognised by the prescribers. The B.P. has so far bowed to the demands of the times as to provide formulae for concentrated liquors which, on dilution with water, yield liquids resembling infusions; but it is specially provided that these should not be used when infusions are ordered.

Infusion of Digitalis is one of the most active preparations of this valuable drug. It should always be freshly prepared, and dispensers should not use concentrated preparations as the equivalent of the fresh infusion. In 1888 Professor Kobert, an authority on the characters of glucosides, showed that in weak alcoholic menstrua the active principles of digitalis undergo such change as to render them almost valueless as heart-stimulants. Apart from this, infusion of digitalis is frequently prescribed because the physician does not wish alcohol in the medicine.

Infusion Of Gentian (Compound)

There is no concentrated liquor in the B.P. to represent this, although it is the most frequently used infusion. The fact is, it is difficult to prepare a satisfactory concentrated preparation which is not more of the character of a tincture than of an infusion.

Infusion Of Senega

A little ammonia is generally added to the concentrated preparation, to prevent precipitation of senegin or its decomposition-products.

Infusion of Serpentary should, preferably, be made from the whole rhizome, because if bruised the starch granules are freed, and thus some of the starch gets into solution, and the infusion strikes a blue colour with iodine. It is sometimes advised to make the infusion with the old rhizome because, unlike the young rhizome, it contains no starch; but the dispenser will seek in vain for commercial varieties known as 'young rhizome 'and 'old rhizome.'