Passing to vegetable substances, the various materials besides rags used in the manufacture of paper may be first noticed. Straw, wood, and esparto fibre, if not exactly waste products, were at least undeveloped substances before they • became, as they now are, so largely used In paper making. Old ropes, flex and jute-mill waste, old or torn pieces of paper of every kind, are all serviceable in paper-mills or in the manufacture of millboerd. In the pulp of the latter old newspapers bulk largely. Cotton waste is much used by mechanical engineers for cleaning purposes. Sawdust is employed in several ways: in the manufacture of artificial wood, which is pressed into many tural forms: as a source of oxalic acid, and of pyroligneous acid; and, when compounded with magnesium chloride, as a durable, warm and resilient coating for the cement floors of fireproof buildings. Chips of yellow pine from Southern shipyards yield turpentine and rosin to the waste industry. One of the most teresting developments of all is the tuts of artificial silk from the wood waste of and carpenter shops. ' The timber wastes of the United Stones are prodigious; the estimate for 1913 placing the total at 150, 000,000 tons. One of the most effective activi ties of the Forest Service is directing the sal vaging of this waste and its delivery into the hands of establishments which will utilise it. The waste liquors of the wood-pulp industry yield alcohol, adhesives, tanning agents and thymol; and a recently discovered Norwegian process for separating the lignin makes that substance available for fuel— in amount nearly or quite enough to furnish all the heat required in making the pulp. Molasses, a waste product of sugar making, besides being a food, yields large quantities of industrial alcohol at low cost; and, as a by-product to this manufacture, yields valuable potash salts. Coricanter's waste has become of high importance in the manu facture of linoleum and cork carpet. Cork mattresses and life-preservers, compressed with shellac into new bottle corks, for lining re frigerators and as a substitute for shavings in vinegar making. From the bark stripped from osier wands the useful medicine salion is now made. In days not so long past the spent mad der of our large dyeworks was suddenly raised from a useless to a valuable material by treat ment with sulphuric acid, which convened it into the dye called garanan. One of the most interesting examples of what has been dome in converting a waste animal product into a highly useful material is seen in the case of waste silk. Cocoons do not yield half their weight of reeled silk, but the remaining °wastes por tion has, through the ingenuity of an English inventor, become the raw material for a large spun silk industry. In Venice artificial flowers for ladies' headdresses are made of imperfect cocoons. The various kinds of waste from woolen mills and from the cutting up of woolen fabrics are either worked up again, the short fibre into mango and the long fibre into shoddy, or it is used for felt or ground into flock for paper hangings. Glue (q.v.) is made from par
ings of hide and bone, which also yield glycerine. The turnings and dust of the ivory and bone turner have various useful applications. From almost any waste animal matter, such as par ings of horns and !mail. hair, blood, leather cuttings and even field mice, is made the whole list of the invaluable cyanides. The waste of leather cutting is compounded with waste or scrap rubber in the production of a water proof artificial sole leather. Clippings of fur skins are made into hats and fish scales into artificial pearls. The waste of mother-of-pearl left by button cutters Is converted Into a fine powder of peculiarly beautiful silky lustre, and used in making artificial flowers and fine wall papers. The skim-milk residue of butter fac tories is made into a grade of condensed milk or treated as a source of commercial casein, the whey being worked for its content of milk . The waste bone-charcoal of the sugar sugar is treated with sulphuric acid to make the valued bone phosphate fertilizer. Other materials regularly dealt in by the dealers in waste include old twine, old oilcloth and car pets. books and magazines, old hats, broken glass and old bottles, moss, hair, fur, bones and many others.
The enormously increased prices following the entrance of the United States into the S\'orld \Vat- gave a market stimulus to the waste industry, owing to the increased values which waste assumed. The larger establish ments found it profitable to organize individual salvage departments, in some cases costing into the trillions; equipped with complete outfits for treating all sorts of waste. A salient ex ample is the General Electric Company's great plant at Schenectady. The report for 191r) showed that the waste department had handled it; that year 80,003,000 pounds of waste, of which 15,000,000 pounds was of scrap metal. Other materials brought to the salvaging shop com prised fibre, rubber, rope, rags, burlap bags and wrappings, remnants of leather belting, as bestos boards and paper, trimmings of cloth. excelsior, box shooks, barrels and barrel staves, etc. Such material as was useless for any other purpose was used as fuel under the boilers, and supplied 53,000,000 pounds of steam in the year.
Smaller establishments disposed of their waste at good prices to one of a large and com petitive throng of dealers. The v.aste trade has its own directory which lists more than 25,000 concerns who either deal in wastes or who use these wastes as raw material in their own industries. Some 1,200 of these dealers are in foreign countries, and not ou:y sell their own domestic waste, but buy at good prices the wastes of American industries.
The trade supports a monthly periodical de to its tilt( s. Consult Koller. T.. 'The n of V. —te Products' (London IQ1R).