Mucilago Dextrini (N. F.)—Mucilage of Dextrin.
Preparation.—"Dextrin, three hundred and thirty-five grammes (335 Gm.) [11 ozs. av., 357 grs.]; water, a sufficient quantity to make one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏]. Mix them in a tared vessel, and heat the mixture, under constant stirring, to near boiling, until the dextrin is dissolved and a limpid liquid results. Then restore any loss of water by evaporation, strain the liquid through muslin, and allow it to cool short of gelatinizing, when it will be ready for immediate use. Note.—If the mucilage is not at once to be used for preparing emulsions or other mixtures, transfer it, while hot, to bottles, which should be filled to the neck. Then pour into each bottle a sufficient quantity of olive oil to form a protecting layer, and when the mucilage has gelatinized, securely cork the bottles, and keep them in a cool place, in an upright position. When gelatinized mucilage of dextrin is to be used for the preparation of emulsions and other mixtures, pour off the protecting layer of oil from the surface, remove the remainder of the oil by a pellet of absorbent cotton, and warm the bottle gently, until the mucilage is liquefied. Then allow it to cool short of gelatinizing. The kind of dextrin suitable for this preparation is the commercial, white variety, provided it still contains some unaltered or only partially altered starch, and forms a jelly on cooling, when made into a mucilage after the formula above given. The yellow variety, which is completely soluble in about 2 parts of cold water, will not answer the purpose"—(Nat. Form.).