I think we are all a bit confused here. Lye was used with fat and boiled to make soap. In the Civil War Era and afterward, women took the dirt from the smokehouses where the salt had dripped from hams, etc . They leached it with water to obtain the dissolved salt. ( the salt dissolved into the water, the dirt didn't ) Then they boiled the water off and had pure salt, which they used for cooking and preserving meat, if they were lucky enough to have any. Leeches, as used medically, are worm like creatures which live in water and attach themselves to the skin of animals and humans and suck out blood. They were used medically to remove hematomas (blood filled bruises) and in the days of "bleeding " patients to supposedly remove diseased blood. Emma In NM