TRKES OF AMERICA. 21 



most of the fires are made of coal- But we 

 must come back to our oaks again, boys ; can 

 you tell me some more of the uses to which 

 they are put ?" 



" I know that the bark is used at the tan- 

 yard for something ; but I do not know what 

 good it does to the leather." 



" Well, then, I will tell you ; oak bark con- 

 tains a great deal of tannin, which has the 

 property of giving consistence and toughness 

 to skins, and making them last much longer 

 than they would without it ; the tanner puts a 

 quantity of the bark, ground up fine, into water, 

 which after a while becomes very strong of the 

 tannin ; then the hides are soaked in this water 

 for several days, and so they become leather." 



" Ah, then, Uncle Philip, that is what the 

 boys dip their hands into the tan-vats for, 

 when they are afraid of getting a whipping 

 at school." 



" Well, I suppose it is ; but it is of no use, 

 for the whipping will hurt just as much ; they 

 had better behave well and never get whipped 

 at all." 



" Uncle Philip, is not the bark of the other 

 trees good for tanning ?" 



" Yes ; most of the barks have a portion of 



