22 FOREST PRODUCTS LABORATORY. 



TURPENTINE AND ROSIX. 



Very valuable results have been obtained by experimental field work 

 in improving methods of obtaining crude turpentine from the tree. A 

 new method has been developed which has increased the yield of turpen- 

 tine and decreased the bad effect on the tree and reduced the danger from 

 fire. This method has been adopted by almost the entire industry. A 

 complete study has also been made of the amount and composition of 

 the turpentine from several western pines. The changing conditions in 

 this industry due to the rapid depletion of virgin stands of long-leaf pine 

 make it desirable to develop turpentining methods which are especially 

 applicable to second-growth timber and to long-continued operation on 

 the same tree, instead of the usual three to five year operations. 



ETHYL < GRAIN) 'ALCOHOL- 



A promising method of utilizing profitably large quantities of wood 

 waste depends upon the conversion of the cellulose into ethyl alcohol. It 

 has long been known that wood cellulose can be converted into ferment- 

 able sugar by suitable treatment with dilute acids at high pressures, but 

 until recently the process has not met with commercial success. Inves- 

 tigation at the Laboratory involved the design and installation of appa- 

 ratus of semicommercial size and a detailed study of the influence of such 

 variables as pressure, temperature, time concentrations of acid and 

 water, and many others. Partly as a result of these experiments the 

 process is now a commercial success and offers a new means of utilization 

 which will be a source of heat and power of immense economic importance. 

 The two plants now operating in this country have a combined daily 

 capacity of about 9,000 gallons of 95 per cent alcohol. The high quality 

 and purity of the products are attested by the great demand for this 

 alcohol for the preparation of pharmaceuticals and colognes. 



SAWDUST FOR STOCK FOOD. 



Another study that has recently been started is the production of a 

 stock food from sawdust. As in the manufacture of ethyl alcohol, the 

 cellulose is first converted into sugar by treatment under pressure with 

 dilute acid, and this sugar, after being extracted and boiled down to a 

 thick molasses, is mixed with the sawdust residue. This so-called " wood 

 meal" has been substituted for one-fourth the ordinary grain ration of 

 the cattle, with a resulting increase in their weight and no decrease in 

 the yield of milk. 



..OTHER DERIVED PRODUCTS. 



Other products derived from trees or forest materials, and therefore 

 within the scope of the Laboratory's work, are tannins, gums, balsams, 

 essential oils extracted from the wood, roots, bark, or leaves of various 



