Cutting.—The next thing to be done is to sort and cut the rags into convenient pieces. This work is usually performed by women, who stand at tables, each with a broad knife firmly fixed into it, and inclined at a slight angle, with its back towards the worker. Before the women, are placed wooden boxes, the bottoms of which are covered with coarse wire gauze, the number of the boxes being determined by the number of different qualities of rags desired. Each mill has its own particular method of working, but, as a general rule, the rags are sorted with special reference to their colour, and the material of which they are composed. They are generally cut into pieces of 2-5 in. square. In some places, machines are used for cutting the rags, but though useful for some kinds of paper, they can never supersede hand-cutting for the finer qualities. One chief reason is that with hand-cutting, the rags can be much more efficiently sorted, and imperfect pieces rejected. It is said also that machine-cut rags suffer greater loss of fibre in the treatment that follows than do those cut by hand.
Dusting.--The cut rags are generally passed through a " duster," in order to complete the removal of dust and dirt. The rag-duster is usually a round or octagonal box of wire gauze, strengthened with stays and ribs, revolving inside a wooden box, one end being slightly raised to facilitate the motion of the rage, which enter at the higher and are discharged at the lower end. Occasionally the wire box is made conical. Various forms of duster are used, but they differ only slightly in principle from the one described. If necessary, rags are put through more than one duster, and, in some places, they are put into a "devil" as well, where they are subjected to a much more violent treatment. The "devil," which is of a somewhat similar construction to a thrasher, is used only when the rags are exceptionally dirty. Some manufacturers pass tho dust from the ordinary rag-duster through another made of finer gauze, in order to save the fibre which becomes detached. The loss occasioned by dusting and cutting differs as much as the material the rags are made of; it varies from 6 to 15 per cent.
Boiling.—The next process is that of boiling, though some paper-makers prefer to give the rags a preliminary washing.
The boiling may be accomplished in various kinds of vessels, either stationary or revolving, but the latter are very generally preferred, owing to the fact that a more perfect circulation of the liquor is obtained with them than with the former.
The revolving boilers may be either cylindrical with round ends, or spherical ; if cylindrical, they are usually made to revolve horizontally. Some cylindrical boilers, however, are placed in an
inclined position, and are fitted inside with a spiral band of thick iron, to facilitate the agitation of the rags. All revolving boilers are fitted with hollow journals, through one of which, enters the steam for boiling. The "chemical" used may be lime, carbonate of soda, caustic soda, or a mixture of the two former, which is of course equivalent to the latter. The quantities used, as well as the 5 o 2 pressure, and time of boiling, vary with the character of the rags ; as a general rule, it may be stated that rage require much weaker solutions than esparto and most other materials, as the grease and colouring matter are comparatively readily removed.
The boiling having been completed, the rags must be washed. This is sometimes partially accomplished in the boiler. The rags are taken from the boiler to the washer. This is similar in construction to that described under esparto. The breaking and washing usually occupy 2-4 hours.
Bleathing.—The bleaching of the rags may be conducted in a similar manner to that of esparto. In addition, the method of bleaching with gas, and sour-bleaching, are sometimes resorted to. The former, on account of the great inconvenience due to the escape of chlorine, is but rarely used. It may be conducted in large chambers made of brick and cement or stone, and with a tight-fitting top, connected by a stoneware pipe with the apparatus for generating the gas. This may con veniently consist of stoneware retorts or small tanks of stone, fitted with some arrangement whereby they can be heated. The chlorine is obtained by heating black oxide of manganese with hydrochloric (muriatic) acid, or a mixture of the oxide of manganese and salt with sulphuric acid. Sour-bleaching consists in the alternate treatment of the rags with bleaching-liquor and a weak acid. It is usually done in large chests or drainers. In some mills, the half-stuff is first well soaked with the bleaching-liquor, and then weak sulphuric or muriatic acid is run in upon them ; in others, the reverse takes place, the acid being allowed to saturate the pulp first, and then the bleach is run in. The most economical way would appear to be, first to bleaoh as much as possible with liquor alone, and then to add an acid when this is nearly exhausted. Whatever the method of bleaching employed, the excess of bleaching agent must be got rid of, and this can be accomplished by one or other of the methods before described. The subsequent treatment of the pulp calls for no special remarks ; the time necessary for reducing rags to the proper degree of fineness is, however, generally longer than for esparto.