600 NITRATES. Lustre vitreous. Colourless, white...yellowish. Streak white. Sectile. h = 1'6. o = r5...r6. Taste pungent, alkaline. It does not melt in the matrass at a very low heat; in other respects its reactions are the same as those of natron. It does not effloresce so readily as natron. NaC + H, carbonic acid 35'50, soda 49-98, water 14-52. Analyses of thermonatrite from Debreczin and Vesuvius by Beudant:— Carbonic acid 35-1 33 - 9 49-2 Water u7 Chloride of sodium .... 2-7 Is found associated with natron, which, in efflorescing, be comes thermonatrite. A solution of carbonate of soda, saturated at from 25 0 to 37° c, and permitted to cool slowly, deposits crystals of thermonatrite, while a less saturated solution at a lower temperature yields crystals of natron. In the carbonate of soda of commerce both species are mingled together. The crystals of thermonatrite occur in drusy cavities in the natron, and remain bright while the natron effloresces. NITRATES. 428. NITEATINE.—Nitrate of soda; Phillips. Nitrate do soude ; Beudant. Bhomboedrisehes Nitrum-Salz ; Molis. Na- tronsalpeter; Hausmann. Nitratin ; Haidinger. Bhombohedral. 100,111 = 43 0 40'. r 100. rrJ 73° 27' (fig. 578.) An increase of temperature of 100 c causes rr' to increase about 27'. Cleavage, r, very perfect. Fracture conchoidal, seldom perceptible. Transparent... translucent. Lustre vitreous. Colourless, white, grey, brown. Streak white. Moderately sectile. H = 1-5...2-0. 0 = 2-0964. Taste bitter and cooling. -Deflagrates on burning charcoal. Before the blowpipe on platinum wire melts easily and imparts a yellow colour to the name. Is soluble in thrice its weight of water at 16° c. NaN, nitric acid 63-66, soda 36’44.
