490 PROCEEDINGS OP THE AMERICAN ACADEMY 



I. 2 grm. of sound pine wood heated for 2 hours at 200° gave 11 

 mg. direct and 4 mg. indirect COj. 

 II. The same wood heated for 2 hours more at 200° gave 9 rag. 

 direct, and 3 mg. indirect CO^. 



Although the decomposition was less rapid during the second heat- 

 ing, the ratio between the direct and the indirect carbonic dioxide 

 remained essentially unchanged. 



Before proceeding further, we were interested to determine whether 

 a pure form of cellulose would yield similar results. We therefore 

 made three experiments with washed Swedish filter paper ; and found 

 that a similar, though much more slow, decomposition ensued. 



I. 3 grm. washed Swedish filter paper heated for 3^ hours at 210° 

 gave 4.1 mg. direct and 2.3 mg. indirect COj. 

 II. 3 grm. washed Swedish filter paper heated for 4^ hours at 180° 

 gave 1.5 mg. direct and 2.5 mg. indirect COg. 

 III. 3 grm. washed Swedish filter paper heated for 7 hours at 160"^ 

 gave 0.3 mg. direct and 2.3 mg. indirect COj. 



Swedish Filter Paper. 



Milligrams of COg in one Hour 

 Temperature. for each Gram. 



Direct. Indirect. 



With decayed pine wood, a portion of sample D mentioned in the 

 preceding paper, we obtained the following results : — 



I. 1.5 grm. of the wood when heated for 1 hour at 196° gave 12 

 mg. direct and 4.3 mg. indirect CO,,. 

 II. 1.5 grm. of the wood when heated for li hours at 180° gave 

 10.6 mg. direct and 4.3 mg. indirect CO2. 



* Keferred to original weight of air-dried wood. 



