Address delivered by Joseph Walsh, M.D., member of the Pharmaceutical Association, D.C., and of the National Pharmaceutical Association, U.S : before the regular meeting of the Pharmaceutical Association, D.C., on the first July, 1857.

  • Walsh, Joseph, M.D.
Date:
1858
Catalogue details

Licence: Public Domain Mark

Credit: Address delivered by Joseph Walsh, M.D., member of the Pharmaceutical Association, D.C., and of the National Pharmaceutical Association, U.S : before the regular meeting of the Pharmaceutical Association, D.C., on the first July, 1857. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    The ingredients which usually enter into the composition of Mixtures are salts and other solid bodies which are soluble in, or easily mixed with, aqueous menstrua, together with Tinctures, Spirits, Syrups, Infusions, Decoction,, and Distilled Waters. In preparing a Mixture, the Dispenser has to consider how he can best effect the solution of solid substances which are soluble—the equal diffu- sion of those which are insoluble, throughout the Menstruum, and the in- timate admixture of all the ingredients of whatever kind, so that every dose, when taken, shall be of similar composition. It is not necessary, nor is it always desirable or even practicable, to mix the ingredients in the order in which they are named in the prescrip- tion. The Dispenser is expected to exercise his judgment in determining the best method of effecting the combination. Pulveres.—The ingredients of powders are mixed in a mortar or on a smooth piece of paper. As a general rule, a mortar should be used, except when the prescription is for one dose, or- Avhen the quantity used is so small that it is necessary to avoid losing the portion that would adhere to the mortar and pestle. It is important in all cases, that the admixture of the ingredients should be effected as completely as possible, and more es- pecially when, as is often the case, the ingredients are of very unequal derees ofactivity. The order in which Powders are to be mixed is the reverse of that which is adopted in introducing the ingredients of a Mixture into the bot- tle. Instead of beginning with the least bulky ingredient, the most bulky, or I should rather say, the most inactive ingredient, should be put in first, a,nd the more active on to the top of this. The object in this is, to avoid as much as possible, the loss of any part of the active ingredients by their combination being taken up in the pores of the mortar. The com- bination is effected by trituration, which should be continued long enough to insure the perfect distribution of the ingredients—due regard being paid to their activity, bulk, specific gravity, $c. Substances of various texture and density are associated in prescrip- tions : Such as crystals, gum resins, leaves, and roots; and as it is a common custom to pulverize many of the substances after they are weigh- ed, the Dispenser has to exercise care and judgment as to the order of their introduction into the mortar. When Camphor is to enter Powders, it should be first thoroughly broken up by the addition of Spirits of Wine; then, if any other substances require trituration, the Camphor is removed from the mortar, and these are reduced to powder. The Camphor is then