50 



BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 



Series V. 



ACID TO WOOD RATIO. 



125 per cent of H2O; 7.5 atmospheres; minute. 



Cook No. 



Sulphuric 



acid (per 



cent of dry 



wood). 



Yield of volatile acid (percent of dry 

 weight of wood). 





Acetic. 



Formic. 



Both. 



38 



0.5_ 

 .75 

 1.00 

 1.40 

 1.40 

 1.80 

 1.80 

 2.50 

 2.50 

 4.00 



0.87 



1.43 



1.05 



1.457 



1.56 



2.11 



1.38 



1.755 



1.67 



2.43 



0.430 

 .253 

 .443 

 .355 

 470 

 .480 

 .642 

 .572 

 .790 

 .735 



1.30 



37 



1.683 



35 



1.493 



33 



1.812 



40 



2.030 



34 



2.59 



30 



2.022 



31 



2.827 



45 



2.460 



36 



3.165 







o o 



uj 4 



at * 



t/5 



w 3 













































































/ 























1 



/ 

 / 























/ 

 1 

























1 

 1 

 1 

























1 



1 



I 

























I 

















































0.1 



0.2 



0.3 



0.4 



0.5 



YIELD IN % OF FORMIC ACID ON DRY WEIGHT OF WOOD 



Fig. 10.— Series lb, showing the variation in formic-acid yields, with varying cooking pressures. 



period, minutes. 



0.6 



Cooking 



Both the yields of acetic and formic acid varied with the cooking 

 conditions, although the former was the more constant of the two. 

 The variations in the water to wood ratio in general seemed to be 

 without effect on the yields of both acids, and this was to be expected. 

 Increasing the pressure of cooking increased the amount of formic acid, 

 particularly as shown in the curve for series lb in figure 10, and this 

 was apparently due in part to sugar decomposition. Increasing the 



