A contusion or bruise must be treated as soon as received, if one would relieve pain, lessen swelling and prevent the formation of a black and blue spot. Compresses wet with hot water, a light ice bag,* or a lotion of fluid extract of witch-hazel, are the best remedies. A bruise upon the head in the case of a young infant, and especially when followed by paleness and vomiting, is not to be carelessly overlooked, since it is sometimes the cause of convulsions.

* Heat and cold act in the same way upon the blood-vessels, contracting them and preventing the transudation of blood. It is the changes occurring in the blood after leaving the vessels that produce the discoloration.