1910) BAILEY—SAP STAIN IN LUMBER 147 
by steam pipes or by steam exhausts could be arranged so that the 
lumber from the saw could be passed through the tanks on carrier 
chains. 
During the coming summer the writer will extend his experiments 
to include a wider variety of woods, and will conduct experiments of 
a practical nature in a large southern saw mill, to determine the relative . 
advantages of hot water treatment and treatment with chemical 
substances. 
Summary and conclusions 
1. Sap stain is in general produced in two ways, by the attacks of 
fungi and by chemical discoloration. - 
2. Chemical discoloration is produced in sap wood by the activity 
of oxidizing enzymes. : 
3. Hot, humid weather is very favorable to the activity of these 
ferments, and cold winter weather is unfavorable. 
4. Oxidizing enzymes which produce sap stain in wood are 
destroyed and their oxidizing action prevented by a temperature of 
Too® C, = 
5. Treating the sap wood of alder, birch, and cherry with boiling 
Water destroys the oxidizing enzymes in the wood and prevents 
_ Sap Stain. 
6. Treating sap lumber in long tanks of boiling water appears 
to be a practical method of preventing sap stain, and to be well 
adapted to saw mill practice. 
In conclusion the writer wishes to express his sincere thanks to 
” Professor E. C. Jerrrey for valuable assistance in carrying out this 
investigation, to Professor G. E. Osteruovt for advice and sugges- 
tions, and to Mr. W. R. Burzer for material of sap-stained lumber. 
HARVARD UNIVERSITY 
