1918.] AGRICULTUEAL CHEMISTRY AGROTECHNY. 809 



wood chips were used which had beeu souked in pliosphoric acid as a cataly/er. 

 Analyses were made of the moisture content of tlie charge ; weight of distillate 

 and charcoal ; and percentage of total, acetic, and formic acids, settled and 

 soluble tar, wood alcohol, and acetone in the distillate. The conclusions drawn 

 from the preliminary tests are as follows : 



"(1) Under the proper conditions a very high yield of acetic acid may De 

 obtained by the destructive distillation of wood, by using phosphoric acid as 

 a catalyzer. Two and seven-tenths times as much acid as normal was ob- 

 tained in one run. (2) The distillation of wood in the presence of phosphoric 

 acid showed a pronounced tendency to give more wood alcohol. Increases vary- 

 ing frpm 40 to 90 per cent were obtained. (3) The distillation of mixtures of 

 wood and tar under pressure showed that the methoxy groups in the tar can 

 be readily split ofC, forming wood alcohol. Nearly 20 per cent of a possible 

 theoretical was obtained at 90 lbs. pressure." 



A study is being made of the possiblity of recovering the metaphosphoric 

 acid residual in the charcoal, thus making practicable the use of phosphoric 

 acid as a catalyzer. 



Effect of varying certain cooking conditions in the production of sulphite 

 pulp from spruce, S. E. Lunak (U. S. Dept. Agr. Bui. 620 {1918), pp. 23, pis. 

 12, figs. 10":. — In the experiments recorded in this publication the foUowing fac- 

 tors involved in the sulphite process for wood pulp were studied for the effect 

 of variations in them on duration of cooking, yield of pulp and of screenings, 

 bleach consumed, and color and strength of pulp produced: (1) Ratio of free 

 to combined sulphur dioxid, or the amount of lime in the cooking liquor; (2) 

 total sulphur dioxid; and (3) temperature of cooking. 



The wood used in the experiment was Wisconsin white spruce {Picea cana- 

 densis), cut into f-in. chips and screened in the usual way. In order to control 

 the various factors the digester was heated by indirect steam. The best method 

 to judge when the digestion was finished proved to be a color test in wliich the 

 standard was a previously prepared extract of coffee of the desired shade. 

 The methods of analysis are described in detail and a diagram given of the 

 apparatus used. 



The experimental data show that at constant temperature and total SO2 an 

 increase in the combined SO- causes an increase in the yield of screened pulp 

 owing to the more thorough cooking, while a decrease in the combined SO2 

 causes quicker cooking action. The limit to which the combined SO2 can bo 

 decreased to obtain good cooking seems to be about 1 per cent, below which 

 there is a rapid darkening of the pulp produced, and an increase in the screen- 

 ings and bleach consumed.. 



An increase in the total SO2 causes a decrease in the cooking period and 

 greater ease in bleaching the pulp. The screenings and color of the pulp remain 

 constant, as the total SO2 is decreased to about 5 per cent, after which there 

 is a rapid inci-ease in both factors. 



A decrease in temperature causes more even cooking, with consequent reduc- 

 tion in the amount of so'cenings and bleach and increase in the yield of pulp. 



Some experiments on the pulping of extracted yellow pine chips by the 

 sulphate process, O. Kress and C. K. Textou (Jour. Indus, and Engin. Chem., 

 10 {1918), No. 4, pp. 268-210; abs. in Chcm. Abs., 12 {1918), No. 10, pp. 1122, 

 1123). — Experiments were conducted to determine whether longleaf pine chips, 

 after the extraction of rosin and turpentine, would be suitable for the manu- 

 facture of kraft paper. 



The results show that a commercial grade of kraft pulp might be made from 

 the chips, but it is evident " that the best results will be obtained if the chips 



