3. _Hard Mineral Substances_ should be formed into an electuary
with some conserve, as they are too ponderous to remain
suspended in syrup. It deserves also to be noticed, that in
consequence of the readiness with which metallic preparations
undergo change, it will be generally adviseable to keep the
active ingredients in the form of powder, and to add them to
the syrup only just before they are required; the Electuary of
the French Pharmacopœia, which is commonly called “_Opiata
Mesenterica_,” will furnish a good example, “_quantumvis molle
fuerit recens, progressu temporis, ob ferrum quod ipsi inest,
mirè indurescit_.”