1919] 



SCIIMITZ STUDIES IN THE DECAY OF WOOD 



105 



this laboratory 



The following table gives the results of 



these determinations: 



TABLE IX 



HYDROGEN ION CONCENTRATION OF THE AQUEOUS EXTRACTS 



Flask no. 



45, 46, 47 



Interval of autoclaving 



Hydrogen ion 

 concentration 



1,2,3.... 

 4,5,7.... 

 8,9, 10.. 

 11, 12, 13 



Not autoclaved 

 45 minutes 



I hour, 45 minutes 



II hours 

 21 hours 



io- 7 



io- 6 



10" 6 

 IO" 6 

 10' 4 



The extract from the unautoclaved Douglas fir sawdust 



practically neutral 

 decided increase i 



With the autoclaved sawdust there 



the hydroge 



ion concentration in the 



extracts as the interval of autoclaving 



Acidity of 



The extracts 



also 



titrated against N/20 sodium hydroxide with the following 

 results. The acidity is expressed according to Fuller's scale 

 each being the average of three titrations. 



TABLE X 



EXTRACTS 



Flask no. 



Interval of autoclaving 



46,47 

 2, 3 

 5, 7 

 8, 9 



12, 13 





Not autoclaved 

 45 minutes 



I hour, 45 minutes 



II hours 

 21 hours 



Acidity 



1.0 

 1.0 

 2.0 

 3.0 

 4.0 



These results correspond with the hydrogen ion determina- 

 tions. A gradual increase in acidity results from increased 



length of autoclaving. 



Effect of autoclaving on the rate of decay induced by fungi. 

 •In order to determine whether or not autoclaving in any way 



of decay induced by fungi approximately 



were placed in 



affected the rate 



equal amounts of western hemlock sawdust i 

 125-cc. wide-necked bottles. The bottles and 

 placed in the hot-air oven and dried 



temperature of 



o 



C. and then weighed. Approximately equal 



