It is believed that Native American people living in northeastern North America were the first to discover maple syrup. They would make V⁠-shaped cuts in the tree trunks using stone tools, and then insert hollow reeds or pieces of bark into the cuts to collect the sap in buckets. To concentrate the maple sap, they would either drop hot cooking stones into the buckets or leave them outside overnight in freezing temperatures to remove the layer of ice that formed on top. Since sugar does not freeze, removing the ice would increase the concentration of sugar in the remaining liquid. Early European settlers learned about the use of maple syrup from the Native Americans and began making it for themselves as well. By the late 1700s and early 1800s, maple sap was being used to produce a concentrated sugar, both in liquid and crystallized⁠-solid form.