10 JoJin White 



any further loss of weight. Heated in the air a further gradual 

 loss was observed. The color changes during the drying from 

 a creamy white to a canary vellow ; when heated in air it goes 

 finally to an orange yellow. When heated in a melting tube, the 

 substance changes to a light sulfur yellow color at a tempera- 

 ture of about 90°C. ; between 95° and 100°, it assumes an 

 orange red hue ; and when heated still higher, it sinters at 

 120° and finally melts, with partial decomposition, to a reddish,^ 

 syrupy liquid at 124° to I25°C. ; on cooling again it solidifies 

 to a lemon-yellow crystalline mass. 



Thus far no satisfactory solvent for the salt has been 

 found ; water decomposes it instantly, yielding first lead iodid, 

 then a basic iodid. Acids all decompose it, giving lead iodid. 

 It is soluble in hot alcohol containing a considerable excess of 

 sodium acetate ; otherwise neither hot nor cold alcohol appears 

 to exert any marked solvent action, but gradually produces 

 decomposition, as shown by the change, in color. Dry ethyl 

 acetate is without efifect, while hot benzol apparently dissolves 

 it in small amount. It is readily soluble in hot nitro-benzol, 

 but does not crystallize out again on cooling. In dry air, as 

 when kept in tightly stoppered flasks, it is apparently perfectly 

 stable, but when exposed to the air under ordinary conditions 

 it quickly turns yellow, the moisture in the air probably 

 causing decomposition ; light is without appreciable action. 



It was stated above that, accompanying the large crystals, there 

 was always found another product, crystallizing in thin, pearly 

 white scales, and that in one instance the coarse crystals were 

 present in the smaller amount. It was at first supposed that 

 the thin flakes were chiefly sodium acetate, but a qualitative 

 test having shown a high iodin content, the substance was 

 examined more closely. Although this substance is an invar- 

 iable constituent of the product obtained through the action 

 of sodium acetate upon lead iodid, it was obtained in very 

 small quantity in all except the one case previously noted, and 

 the exact conditions for its preparation could not be determined. 

 Where present in small quantity, or when the other product 

 is obtained in large crystals, the two could be fairly well sep- 



316 



