Nutmeg is the shelled, dried seed of the plant Myristica fragrans, and mace is the dried net-like covering of the shell of the seed.
Nutmeg and mace are applied to the skin to kill pain, especially pain caused by achy joint(rheumatism), mouth sores, and toothache.
While cooking, nutmeg and mace are used as spices and flavorings.
When used in excess, this acts as a narcotic and could even be poisonous. So, limit your culinary usage to a pinch or two each time.