[ 4 ] ment, the operator might have an opportunity of difcovering the contents of an unknown fubftancc in a third way. SECTION II. On Mineral Subjlances in general. EXPERIMENT I. i. POUR diftilled water on the mineral fubftance you want to examine; if it diffolves the fame, or part of it, either cold, or infufed with warm or hot water, and put in a veffel in fand near a fire, for digeftion j or by boiling it; and if the water by this means becomes impregnated with particles affedting the tongue with a fharp or pungent fenfation, the mineral fubftance thus examined is of a faline nature, or a kind of SALT. 2. It mud be obferved, that the greater part of pure faline fubftances diffolve readily in water, except felenites and arfenic (which diffolve only by boiling), and fuch fubftances which are commonly called ores ; and which likewife yield their faline particles when in fufed in water, after fome other previous operations afterwards to be mentioned. The mineral fubftances intended for examination, ought to be pounded. 3. Saline fubftances will moft commonly melt ! when put on the fire, and fome of them crackle •, others, on the contrary, will caufe during fufion an ebullition and froth. Fumes arife from them all during the operation. expe.