This preparation was made in order to meet the demand for a soluble form of bismuth, by which its effects on the system might be obtained with greater certainty, and from a smaller dose. Originally made by a secret formula, it was analyzed by Mr. Tichborne, who, having ascertained its composition, devised a method of preparing it, which was afterwards improved by Mr. N. G. Bartlett, of Chicago. For the mode of preparing it, the reader is referred to the IT. S. Dispensatory (12th ed., p. 1028). It is believed to consist of one eq. of teroxide of bismuth, one of ammonia, one of citric acid, and five eqs. of water. In the solid state, it is in transparent colourless scales, of a somewhat metallic but not disagreeable taste, very soluble in water, and of an acid reaction. As first prepared it was in the liquid form, and denominated liquor bismuthi; but this is not necessary, as the compound keeps well, and may be dissolved when wanted for use. The dose of the salt is two grains, that of a solution prepared by Mr. Bartlett, for which a formula is given in the U. S. Dispensatory, a fluidrachm.