Page:Popular Science Monthly Volume 23.djvu/823

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THE SAVINGS OF SCIENCE.

shape of a new black, which is destined to have a variety of important uses, such as in the manufacture of printing-inks, dark pigments, covering substances, and notably for the manufacture of blacking. Bone-black, from which the latter is chiefly made, costs £9 per ton, and the supply is limited, while this new tannic black can be sold at one third of the price.

The blood from the slaughter-houses, which used to be wasted, is now collected in Europe, and utilized for manufacturing into blood albumen, which sells at about 1s. a pound. The drainings and the clot go for manure.

Among the miscellaneous animal substances now utilized, we find many species of fish-skin tanned, such as the so-called porpoise-skin, (Beluga catodon). Alligators and crocodiles, and even snakes, are hunted for their skins, which are tanned, and provide a valuable article for making slippers, purses, pocket-books, cigar-cases, etc.

Let us now pass to vegetable substances, and I will first consider the paper manufacture. A recent estimate was published, which set down the paper-mills of the world at 4,000, producing 1,000,000 tons of paper, of which one half was used for printing.

It is now evident that the future of the paper industry will, in a large degree, depend upon the use of wood, which is already extensively employed. For the ordinary varieties of paper, ground wood is used; but, for the finer sorts, chemically prepared wood-fiber, or cellulose, is employed. The practical process for the preparation of cellulose was discovered in 1852, and numerous other processes or improvements have since been invented. It comes into commerce in two forms—wood-pulp in sheets or blocks, and ligneous meal or wood flour. In Central Russia, aspen-wood is most extensively employed; in Sweden and Finland, spruce and fir, which afford the longest fibers; in Germany, France, and Belgium, mixed woods. The pulp from beech and birch woods has too short a fiber.

About twenty years ago, some of the American paper manufacturers used the bamboo largely for making paper. This is no new application, for the Chinese have long employed it for a common description of paper. Good paper is now also made from esparto-grass.

A good deal of the jute sent from India to the United States consists of the dark root, or butt-ends of the fiber, which are cut off when the jute is pressed into bales. These are called "cuttings" in Calcutta, and with us, "rejections"; they now form a regularly quoted article of export to America, where they are employed in the fabrication of various shoddy-stuffs. In former years these cuttings were thrown away. Megass, the refuse stalk of the sugar-cane, makes excellent paper. The husks of oats, barley, rye, and rice, are also used alone, or combined with other materials. Straw-board, of late years, has been found to be a cheaper material than the old-fashioned "pasteboard," and it has come extensively into use in America for paper-boxes.