The refining consists in extracting the excess of sulphur by means of boiling potash solution; 300 kilogrammes of the ground vermilion are stirred up with water in a tub, the water is drawn off and the wet mass brought into an iron pan, in which it is heated with 22·5 kilogrammes of potash lye for about 10 minutes. According to the composition of the crude vermilion the lye has a strength of from 10° to 13° B. The smaller the quantity of sulphur, the weaker is the potash solution; it is, or was, made in Idria in a very primitive manner, by extracting wood ashes. For vermilion of a bright red shade potash solution of 10°, for the dark red of 11°, and for “Chinese vermilion” of 13° is used. The excess of sulphur, together with a trace of mercuric sulphide, dissolves in the potash solution; the sulphur chiefly forms potassium pentasulphide. When the boiling is finished, the vermilion is carefully washed and dried in dishes placed in a heated furnace. During drying, the vermilion agglomerates; finally the lumps are broken and sieved. =Chinese Vermilion= is in similar case to Indian ink. Both substances are in common use in Europe, they far surpass in quality our own manufacture, and in neither case do we know the exact method by which they are made. Genuine Chinese vermilion so far surpasses European in brightness that it is bought at five or six times the price. It is said on unauthenticated authority to be made by subliming a mixture of 4 parts of quicksilver with 1 part of sulphur in earthenware pots closed by an iron plate, which is kept constantly wet and serves as a receiver, on which the vermilion deposits. The sublimed masses adhering to the lid are sorted, ground and repeatedly washed with water. According to Callum’s description of the manufacture of vermilion at Hong Kong, mercury and sulphur are heated in a large iron pan, with continual stirring at about the melting point of sulphur (111° C.), until the whole has changed to a black mass. After cooling, this is mixed with water and mercury, the mixture thoroughly stirred, dried, placed in a hemispherical dish and covered over with broken porcelain. A similar dish is cemented on the top of the first, and the dishes are heated for 16 hours; the vermilion adhering to the porcelain fragments is removed, wet ground and dried. A vermilion approaching Chinese in beauty is said to be obtained by mixing ordinary vermilion with 1 per cent. of antimony sulphide and again subliming the mixture. The dark grey sublimate produces a reddish brown powder, which is repeatedly boiled with a solution of “liver of sulphur” (potassium polysulphide), washed with water and digested for a long time with hydrochloric acid. The author has repeatedly made vermilion by this process, but could never obtain a product differing appreciably from the original vermilion. (b) WET METHODS.