Shock, the group of symptoms produced by some profound impression affecting the nervous centres, either directly, as in great mental disturbance, or indirectly, as in the case of severe injury affecting the peripheral nerves. The symptoms of shock are partial or complete loss of consciousness, muscular weakuess, cold, clammy skin, feeble, rapid pulse, quickened respiration, lowered temperature, and loss of control over the sphincter muscles. In the case of head injuries the variety of shock sometimes spoken of as concussion of the brain occurs. [CONCUSSION.] When recovery from the condition of shock sets in, a period of reaction supervenes, with raised temperature. The treatment consists in the maintenance of rest in the horizontal position, in applying heat by means of warm flannels, hot-water bottles, and the like, and, in certain cases, in administering stimulants.