Salty, cold and heavy in weight, Magnetitum (ci shi) enters the Liver and Kidney channels to protect the true yin, anchor the yang which is floating upward, and quiet the Heart spirit. The Kidneys govern the bones and store the essence, and the orifice of the Kidneys is the ears; thus, when the Kidneys are deficient and the essence is exhausted, there will be dizziness, tinnitus, and deafness,or wheezing, as the Kidneys fail to grasp the qi. The Liver governs the sinews and stores the blood, and the orifice of the Liver is the eyes; thus, when the Liver is deficient and lacks blood, the sinews will become weak and the vision will be impaired. Yin deficiency allows the yang to ascend, leading to derangement of the Heart spirit and thus palpitations, forgetfulness, insomnia, and restless activity. In all these situations, Magnetitum (ci shi) can serve as the chief medicinal, because its salty coldness travels into the lower body to nourish the Kidneys, augment the essence and blood, and suppress and contain the floating yang. (from Chinese Herbal Medicine Materia Medica, 3rd ed.)*