Bui. 606, U. S. Dept. of Agriculture. 
Plate VI. 
Penetration in Basswood— Heartwood (Tilia Americana). 
1, piece No. 39 treated 30 minutes; 2, piece No. 40 treated 60 minutes; 3, piece No. 41 treated 
120 minutes. Note the penetration of creosote in the summerwood first, in the piece on the 
left. Penetration took place readily in the summerwood because the wood prosenchyma is 
easily treated in this species. 
