[ 3 4 ] tity of it was difiolved; the undiflblved part proved to be a fourth of the original quantity. *1 his undiflblved refiduum was pounded and calcined with oil of vitriol, till all the fluid was evaporated; and during the operation a quantity of elaftic fumes were feparated. The mafs ■was eafily dilfolved in water, having been pre viously cooled and pounded. By the addition o£fpiritus fahs ammoniaci cum calce no precipita tion was produced ; but a calcareous earth was precipitated upon the addition of fait of tartar. The remaining fluid yielded a tartarus vitriola- tus, becaufe the fal tartari had decompounded the diflolved felenitc. 0. From the above experiment it appears, that the Sparry Fluor is a calcareous earth faturated with its own acid. The alum and iron feem to be fubftances, which are only accidental in the mixture of this mineral body. Diluted acid of fpur \6), upon being mixed with lime-water, precipitated a white powder, which, though not in the form of cryflals, yet had all the properties of the original fpar : For when fpread on a hot ftone it became luminous; it melted by the blowing-pipe, efpecially upon tne addition of a fmall quantity of gypfum ; and laitly, this new fpar could again be de compounded in the lame manner as the original iubftance, by the addition of oil of vitriol. 1. The white cruft (6) formed on the furface of the water in the recipient, had the following properties : ci. It could not be difiolved in any acid. b. When pounded it would not form any pafte with water. c. Upon being boiled with oleum tartari per deliquium, it was difiolved; and when grown cold,