PAPER MATERIALS. The supply of rags is insufficient to meet modern demands, and first esparto (about 186o) and then wood (about 188o) accordingly came into use; the use of wood has been greatly advanced, until nowadays it provides by far the largest portion of the world's paper, and it is to wood that the world looks for the somewhat alarming demands of the future. The total consumption of wood per annum for paper is at present about 40,000,000 tons of, mostly, coniferous wood, from which about 15,000,000 tons of wood cellulose pulp for the paper industries are obtained. Hitherto the forests of Eu rope and North America have met a very large proportion of the whole demand, and mainly by a prodigal process amounting to mere extermination, which has left, especially in North Amer ica, a legacy of difficult economic problems as possibly permanent factors determining ultimate output.
Even now, when so little has been done to conserve what is avail able, it is said that annual growth replaces about 8o% of the amount cut. Improvements and inventions in the chemistry of pulp making may be expected, when required, to make other plant materials more or less as usable as coniferous woods now are. In some regions, and especially where tariffs are favourable, some local materials are already coming into use, increasingly, to supply local needs. Thus, in India there are now five mills, producing in all 33,00o tons of pulp per annum, mainly from grasses and cereals : other mills are projected and interest is being developed in the use of bamboo, a material first tried by Thomas Routledge (who also introduced and established the use of esparto), the use of which was further elaborated and brought to the level of industrial exploitation by W. Raitt, in recent
years. In Burma the paper mulberry, most ancient of paper materials, is beginning to be exploited by plantation methods for the local Indian markets; and similarly in the West Indies, in Brazil, and elsewhere local paper industries are springing up.
It is clearly a gain to the whole world that regional industries should thus spring up to make use of low grade materials for the manufacture of cheap products which will not stand high freights. The supplying of local demands for cheap grades in this sort of way will stimulate a subsequent demand for better grades, which will be met by the supplies from the industrially more organized countries of Europe and North America, as has hap pened already in the textile industries. There is a very large amount of waste cereal material in the several countries of the world which is used for fodder, fuel, and so on : a good deal of this would be available for paper material if and when re quired, and some of it is even now thus used, to a minor extent, for straw boards and some grades of paper to which it gives a hard, brittle quality. The quantity available, both of natural grown and cultivated cereals and grasses, could doubtless be greatly increased. Esparto is already thus cultivated, though the output of it is relatively small, and most of it is derived from the littoral, natural grass lands of the Mediterranean. Actually about 2,000 species of plants, among those already studied and described, are known to be possible sources of fibrous raw mate rials, only a very small number of which have been actually used industrially, except of course by native craftsmen. And when it is considered how the quality and the output of such plants as cotton, wheat, and rubber, have been favourably modified by systematic thorough-breeding and cross-breeding, it appears cer tain that there must be important undeveloped utilities latent in many of these 2,000 species, which it will be possible to de velop by systematic cultivation in due course.