SAP-STAIN, MOLD, AND DECAY IN GREEN WOOD. 



vegetables, cereals, mushrooms, and various soft plant tissues are 

 brought about through the agency of certain oxidizing ferments, the 

 oxidases and the peroxidases (Aso 1^2^ S\ Clark, <S, 9\ Kastle, 27). 

 These ferments are sometimes distinguished by the production of a 

 strong blue color in a tincture of guaiacum v^^hen used in the presence 

 of oxygen or hydrogen peroxid 

 (Haas and Hill, 16, p. 383). 

 Bailey {5) states that the ac- 

 tivity of these oxidizing enzyms 

 increases with the rise in tem- 

 perature to a certain point, 

 which may be called the opti- 

 mum, and then decreases as the 

 temperature is raised above this 

 point. In almost every case, ac- 

 cording to the same authority, 

 the activity is entirely destroyed 

 before a temperature of 100° C. 

 (212° F.) is reached. He also 

 states that the activity of these 

 oxidizing ferments is dimin- 

 ished or destroyed by certain 

 antiseptics and by other chemi- 

 cal substances. According to 

 Aso {1,-2), such substances as 

 tannin, sodium fluorid, and so- 

 dium silicofluorid, interfere 

 with the color reactions nor- 

 mally produced by oxidases. 

 Bailey (5) notes the strong 

 similarity existing between the 

 oxidizing activities of these en- 

 zyms and the chemical reactions 

 responsible for certain kinds of 

 sap-stain, namely, post-mortem 

 oxidation with change of color 

 produced by solutions in con- 

 tact with the air and the similar variations in the activity of the 

 discoloring agency in relation to variations in temperature. 



If discolorations in sapwood are due to the activity of oxidizing 

 enzyms, which, as has been shown, are rendered inactive by exposure 

 to a temperature of 100° C. (212° F.), a logical prophylactic measure 

 would be the submersion of timber in boiling water. Bailey (5), 

 during the spring of 1910, performed certain dipping experiments. 



Fig. 1. — Board of sugar pine, showing 

 chemical stain. The unstained area in 

 the lower half of the illustration indi- 

 cates the position of a crosser during the 

 kiln treatment. The crosser afforded pro- 

 tection from oxidation. Photographed by 

 H. D. Tiemann. 



