OXIDIZING ENZYMES AND THEIR RELATION TO 
“SAP STAIN” IN LUMBER" 
TRVING “Wi. BAILEY 
The discoloration of sap wood, or “sap stain” as it is common 
In endeavoring to prevent the discoloration of sap wood it is ¢ 
fundamental importance to discover what agency or agencies 
duce the stain, and to study their mode of activity. 
So far as the writer has been able to determine, there are in gen 
two agencies which produce the discoloration of sap wood. On 
these, which is of frequent occurrence and of great economic impor- 
tance, is a purely chemical reaction which takes place in green 
lumber upon exposure to the air (oxygen). This chemical discolora- 
tion occurs. in many varieties of wood, and is well illustrated by 
reddish yellow or rusty colored sap stain which occurs in the S# 
wood of alder, birch, and cherry, and by the blue colored sap sta! 
which occurs in the sap wood of red gum (Liguidambar). Whe 
the freshly cut surfaces of these woods are exposed to the air, und 
favorable conditions of temperature and moisture, a chemical reaction 
warm weather, and optimum Conditions during extrem 
humid, summer weather, when lumber becomes discolore 
a few hours. The examination of microscopic sections of this : 
stained lumber reveals the fact that the colored substance, produceé 
by the chemical reaction, is most conspicuously developed in the W' 
rays and wood parenchyma cells, living tissues which are ‘4% 
concerned in the storage and conduction of food in the wood. — 
* Contributions from the Phanerogamic Laboratories of Harvard Unive? 
. 26. oe 
Poe 
Botanical Gazette, vol. 50] 
