1919] 



SCHMITZ — STUDIES IN THE DECAY OF WOOD 97 



It is of special interest to note that Bacillus amyl ob act er , 

 as shown by Van Tieghem (77), does not dissolve the cellulose 

 from all plants, and also the fact, as indicated by Omelianski, 

 that with the forms worked on by him the power to dissolve 

 cellulose decreased as the age of the cultures increased. 

 McBeth and Scales ('13) found that cellulose-dissolving bac- 

 teria are universally present in cultivated soils. 



That even the ordinary saprophytes may, under some con- 

 ditions, affect some of the components of the cell wall, is shown 

 by van Hall ( '02). He found that Bacillus subtilis and B. vul- 

 gatus could produce a rot on potatoes, turnips, and various 

 nuts at a temperature of from 37 to 42° C. and that the middle 

 lamella was dissolved. Potter ('04) also found that in the 

 decoction made by boiling the alburnum of oak wood Bacillus 

 subtilis could grow and utilize the extracted substance (lignin). 



Experimental Work 

 the effects of autoclaving wood 



Color changes induced in Douglas fir and western hemlock. 



Equal amounts, 2.000 gms., of fine Douglas fir sawdust were 

 placed in 125-cc. Erlenmeyer flasks and 25 cc. of distilled wa- 

 ter were added to each. The flasks and contents were then 

 weighed to the closest 0.1 gram preparatory to autoclaving, 

 so that if any change in weight took place during autoclaving 

 the flask could be restored to its original weight by the addi- 

 tion of distilled water, any change in the intensity of color 

 then not being due to an increased concentration of the con- 

 tents. The same methods were followed with western hem- 

 lock sawdust. 



Some flasks and contents were not autoclaved ; others were 

 autoclaved for increasing intervals from forty-five minutes 

 to twenty-one hours and the change of color noted. The col- 

 ors are those of Ridgway ( '12). 



In both cases it is evident that a decided darkening 

 as the length of autoclaving increases. For the purposes of 

 sterilization twenty hours of autoclaving are not necessary, 

 yet there is a marked change in color caused by forty-five 

 minutes of this treatment. The exact nature of these changes 



