Investigations have been carried on at the Forest Products Laboratory in making artificial silk from sawdust. The industry has already attained considerable proportions. It consists principally of converting cellulose into viscose, which, in turn, is manufactured into an almost endless number and variety of silk and other goods varying from sausage casings to silk hose and tapestries. Sawdust is used also in the manufacture of inlaid linoleum and dynamite. Experiments in naval stores are attempting to improve the old methods of harvesting turpentine, which have proven very destructive to the forests. With the approaching exhaustion of the Southern Pinery as a field for the naval stores industry, it has become more and more important to find other species for this purpose. Consequently the Laboratory has conducted experiments with the various pines on the National Forests in California, Colorado, Arizona, and New Mexico. [Illustration: Figure 32. A plank of Incense cedar affected by a disease known as "pin rot." By cutting the cedar timber when it is mature this can be largely avoided. Lassen National Forest, California. Photo by the author.] [Illustration: Figure 33. The western pine forests will some day be a great source for naval stores. By distilling the crude resin of the Jeffrey pine a light volatile oil--abietene--is secured which has great healing and curative properties. Lassen National Forest, California. Photo by the author.] A great many pulp and paper investigations are also conducted by this Laboratory. The large size of the industry and the threatened exhaustion of the native spruce forests which furnish the principal supply are circumstances which call for intensive investigations. About nine-tenths of the paper which we use is made from wood, and the amount of wood which is converted into paper annually has reached almost 5,000,000 cords. There are over 2,500 newspapers in the United States, and it is said that a single issue of a New York Sunday paper consumes the trees on about 15 acres of forest. The main object of the work at the Laboratory has been to use other species of wood for the manufacture of paper to offset the fast waning supplies of spruce. Poplar, hemlock, pine and balsam are now being used in considerable quantities. News and wrapping paper has also been successfully made from many National Forest species, including Sitka spruce, Western hemlock, Engelmann spruce, Red fir, White fir, and Lodgepole pine. Kraft paper has been made and manufactured into suitcases, bags, wall coverings, twine, and similar articles. Not only has the Forest Products Laboratory brought into use species of trees never before tried for paper making, but it has also improved some of the old methods of paper making to such an extent that the results have been adopted by various large paper mills.