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Concentrated Infusions

These are now very generally met with in trade, and are made of 8 times the pharmacopœial strength. They are mostly prepared by employing 8 times the usual quantity of ingredients, and only three-fourths of the proper quantity of water, and adding to the strained liquor, when cold, sufficient spirit of wine to bring the liquid up to the proper strength (about one-third of the weight of the strained infusion). A still better plan is to treat 8 times the usual quantity of the ingredients with a mixture of rectified spirits 1 part and cold water 3 parts; in the usual way for making tinctures, either by maceration for 7 to 14 days, or by percolation. Concentrated infusions made in this way keep well, and deposit scarcely any sediment. Many houses, that are remarkable for the brilliancy and beauty of these preparations, employ onethird spirit of wine and two-thirds water as the menstruum. It may, however, be taken as a general rule, that for vegetable substances that abound in woody fibre, and contain but little extractive matter soluble in water (as quassia for instance), one-sixth to one-fifth part of spirit is sufficient for their preservation; while for those abounding in mucilage or fecula, or that readily soften and become pulpy and glutinous in weak spirit (as rhubarb), one-fifth to one-third is required. By macerating in the infusion as much bruised