The Celts long held the belief that Oak is the tree of doors, that can be used as the gateway between worlds as well as a place where portals could be erected. The Norse held oak to be sacred to Thor, perhaps due to how often the tall trees were struck by lightning. Similarly the ancient Greeks also revered it as a sacred symbol of Zeus. Native Americans of old used to gather the acorns of the trees, and use them to grind into flour or store as provisions to help them through the winter, while the bark was used by tanners in the preparation and tanning of leather.
Today, while the wood is often used for fine furniture and cabinetry, the bark is actually being explored as a healthy dietary supplement. It contains vitamin B12, as well as the minerals of calcium, iron and zinc, and has been used often in natural skin creams. Some herbalists also believe white oak bark to be useful in treating ulcers, spleen problems, and diarrhea. Indeed, old herbalists' lore often refers to a tea that was brewed from the bark for the treatment of internal bleeding. Externally, there are wide variety of uses, including the treatment of rashes, skin infections, swollen glands, sores and similar such ailments.