32 



BULLETIlSr 1037, U. S. DEPARTMENT OF AGRICULTURE. 



in or upon the blocks by means of a sterile scalpel and needle gave no growth, 

 while cultures taken from check blocks which had not been steamed gave positive 

 results in every case. 



Steamed material, unless open piled under conditions which insured an ample 

 supply of circulating air, molded almost as readily as green stock. 



Steamed blocks that were given a month's air drying subsequent to steaming 

 and previous to storage under the extreme conditions that prevailed in the tile 

 chamber showed a little more resistance to the invasion of fungi than those 

 blocks that were placed in the tile chamber immediately after steaming. 



It is quite probable that the steam treatment of wood stock, fol- 

 lowed immediately by prolonged submersion of the material in some 

 of the antiseptic solutions to be described later, might prove to be a 



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Fig. 13. 



-Boards of red g:um loaded on a truck and ready to be rolled into the prepa- 

 re tor (shown in fig. 14). 



fairly effective method for the control of fungi in infected stock. 

 This treatment might be applied to special classes of wood stock 

 where the margin of profit would justify the extra cost. 



THE CHEMICAL TREATMENT OF GREEN WOOD STOCK. 



Many attempts have been made to find some chemical compound 

 or mixture that, when applied as a dip, will control sap-stain and 

 mold in green timber. A great many substances have been tried, bat 

 none have proved entirely satisfactory. Under conditions not par- 

 ticularly favorable to the growth of fungi, several have met with 

 considerable success. On the other hand, if the conditions were 

 stimulating to fungous growth, the same substances often failed. 

 Some treatments depend for their efficiency upon the neutralization 

 of the acids in the wood and, at the same time, the establishment of 



