Boil two good handfuls of log-wood with a little sumach and elder bark for an hour, put in the stuff or hackles (boil very gently), bruise a piece of copperas about the size of two Spanish nuts, put it in with a little argil and soda; take out the hackles and hold them in the open air a little, then put them in again and leave them all night gently heated, wash the dye well out of them and your black will be fine. The argil and soda soften the dye stuff of the copperas, but a small quantity must be put in.