20 BULLETIN 620, U. S. DEPARTMENT OF AGRICULTURE. 
only about 0.5 per cent. This probably is due to a decrease in the 
amount of hydrolysis of the cellulose occurring under 120° C. The 
screenings decreased with the temperature. The explanation for this 
is that with the higher temperature the cooks are finished before the 
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80 120 160 200 O 10 30 44 46 48 so 
PARTS BLACK DURATION OF eacce: HOURS YIELD OF UNSCREENED 
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Fic. 10.—Effect of varying the temperature of cooking. 
inner portions of some of the larger chips are thoroughly cooked, while 
the smaller ones are probably overcooked. The lower temperatures 
with their longer cooks insure a more even cooking and therefore 
produce less screenings. Decrease in the temperature produced a 
