Bromides, salts of bromine with various radicals, of which the most important are those found with potassium, sodium, ammonium, lithium, iron, and mercury. The alkaline bromides crystallize in cubes or rectangular prisms, and are very soluble in water. These are considerably used in medicine. Bromide of potassium in large doses (20 to 60 grains) produces sleep, as has been supposed, by giving rise to anaemia of the brain. The reflex excitability of the nervous centres in general, and the spinal cord in particular, is much diminished, and in frogs may be destroyed before the power of voluntary motion is lost. They are used to relieve sleeplessness and nervous excitability, and in various diseases characterized by increased reflex activity, of which epilepsy is the most important. This disease is often controlled, and seems sometimes to be cured, by the continued use of bromides. They have also a sedative effect on the genital organs. The bromides have been used as alteratives.