"Well, we can get the bark; I know where there are several oak trees, and also a number of beech trees."
"Then gather the bark by all means, and by the way, if you can find gall nuts we could use them to advantage."
"We don't know what they are."
"Then, if you can get some sumac, we can use that."
"Yes, I know; the kind with the long, red leaves."
"That is what I mean."
"Do the gall nuts have tannic acid?"
"Yes; but principally gallic acid, but gallic acid will also tan the skins so as to make leather. The principal use of the gall nut is for making ink."
"What kind of tree does the gall nut grow on?"
"On any kind of tree or bush."