t I* ] rated by fumes. Then pour a fufficient quantity of diftilled water on it ; and after it has dif- folved all the faline particles of the infufed fub- ftance, decant it into a flat glafs, cover it, and put it on a warm place for evaporation, till it forms cryftals, which may be kept for the fol lowing experiments. 40. Care muft be taken not to employ any copper, brafs, or iron veflels, to diflblve,, boil, or evaporate falts in; becaufe their acids often unite readily with the particles of the veflel, and thus fpoil the experiment. Lead may be employed; but glafs, porcelain, or glazed earthen veflels, are the beft in fmall aflays. 41. A great many faline fubftances may be judged to be fuch, by bare infpedtiori and by tailing them ; and as they do not want any previous calcination, becaufe they are not united with fulphureous or arfenical par ticles, they may be immediately employed for the Experiments hereafter to be men tioned. Some which are lefs pure may be diflolved in w.ater, {trained through blotting- paper, and then evaporated till cryftalliza- tion enfues. If the faline particles will not readily diflblve in cold water, hot or boiling water will fometimes do it. experiment XIV. 42. If the cryftallized falts extrafted from an ' ore, according to Experiment XIII. have a ftyptic, adftringent tafle, and be either white, rofe-coloured, green, or blue, and their folu- tion will ftrike an infufion of tea or galls purple-colon red or black, it is evident that they are vitriolic metallic falts. In the firft and