Enquire within upon everything by Robert Kemp Philp

668. Care of the Mortar.

Be careful not to pound too hard in glass, porcelain, or Wedgwood-ware mortar; 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 substances in any but a brass mortar.