[Vol. 6 



94 ANNALS OF THE MISSOURI BOTANICAL GARDEN' 



Survey of Literature 



EFFECTS OF AUTOCLAVING WOOD 



The different viewpoints in regard to the effects of sterili- 

 zation upon woody tissues are indicated by the works of Pot- 

 ter ('04) and Spaulding ('06). The earlier workers in this 

 field were primarily interested in the determination of the 

 chemical compounds present in woody tissues. Thus, Singer 



( '82) extracted four distinct substances by means of boiling 

 water: vanillin, a substance giving the reactions of coniferin, 

 a water-soluble gum, and also a substance giving a yellow 

 color with hydrochloric acid. Van Wisselingh ('98) found 

 that after treating slices of Beta vulgaris with distilled water 

 at 125° C. for six hours a wall of pure cellulose remained, 

 while the pectin substances were decomposed and dissolved. 

 Even at a temperature of 100° C. the tendency for water to de- 

 compose and dissolve the cell wall was noted. 



Potter ( '04) tried the effect of hot water on different woods, 

 Quercus, Ulmus, Alnus, Aesculus, and others, and found that 

 steaming had a decided effect on the cell wall. It was shown 

 that the action of boiling water caused a delignification of the 

 xylem. The watery extract obtained from sawdust and frag- 

 ments of wood when treated in this manner contained a sub- 

 stance which reacts to the lignin tests. Still further, it was 

 shown that cold water, operating for a longer period of time, 

 had a similar power of extracting from the xylem a substance 

 which reacts with phloroglucin and thallin sulphate, and thus 

 by continued soaking in water wood undergoes a partial de- 

 lignification. If this be true, then autoclaving, even for the 

 time required for sterilization, may have a marked effect on 

 the wood when used for experimental purposes with reference 

 to decay induced by fungi. 



Rose and Lisse ( '17) have made chemical analyses of sound 

 Douglas fir and of the same wood in various stages of decay. 

 Their results showed a rapid decrease in the percentage of 

 cellulose as decay proceeded, while the lignin seemed to be 

 far more resistant. They do not state what fungus caused 

 the decay of the wood upon which they worked, and for that 



