A LABORATORY EVALUATION OF WOOD PRESERVATIVES 201 



Materials to be tested as possible preservatives are injected in serial 

 concentrations into the blocks of sapwood, commonly southern pine, 

 under conditions simulating as nearly as possible those which would 



Fig. 6 — Constant humidity chamber filled with test blocks. 



be used in practice. Due to the variance in the moisture pick-up of 

 wood at different relative humidities, it is necessary to bring the blocks 

 to equilibrium under standard conditions both before and after the 



