False alicorn powder, made from the tusks of narwhals or horns of various animals, has been sold in Europe for medicinal purposes as late as 1741. The alicorn was thought to cure many diseases and have the ability to detect poisons, and many physicians would make "cures" and sell them. Cups were made from alicorn for kings and given as a gift; these were usually made of ivory or walrus ivory. Entire horns were very precious in the Middle Ages and were often really the tusks of narwhals.