1 If you add music and files to your iPod while you are charging the battery, it will take longer for it to charge. 2  Before using your iPod nano for the first time, it is important that you let it charge for a minimum of three hours. 3  If you do not, you can weaken the battery, giving it a shorter lifespan.
Too much iron will usually turn the blood black. However, if there is liver failure, and it's seeping into the blood stream that too can cause the blood to turn black as it becomes over loaded with toxins. Put simply it's the blood is overloaded with toxins and other nutrients that the body can't process entirely.
Black toenails are caused by trauma to the nail. Common causes of toenails turning black include ill-fitting shoes, fungus, dropping an object on the toe and cutting the nail too short. Impact to the toenail causes bleeding underneath the nail's surface. Part or all of the toenail may turn black.