It appears from the record that Harris knew that the account on which he was sued by the Macon Paper Company contained the credit claimed by him against the Jacksonville Paper Company and that the credit was necessarily allowed *Page 767 him in the action on the account. In these circumstances it seems to me that in equity and good conscience Harris is now estopped to deny that he has received the benefit of the credit, and is precluded from receiving the benefit of the sum a second time.