A sacramental blessed by a priest to invoke God's blessing on those who use it. There are four kinds: ordinary holy water, blessed by the priest for the sprinkling of the people before Mass (see ASPERGEs), for use at the door of the church, and for the blessing of persons and things in the church and at horne, sometimes used with salt, as a symbol of wisdom and of preservation from corruption; Baptismal water, in which the oil of catechumens and the holy chrism are mingled, used only in the administration of Baptism; water of consecration, or Gregorian water, and Easter water. As used in nearly all the blessings of the Church's ritual, it is usually contained in a bowl-shaped vessel having a swinging handle and provided with a sprinkler. At the church door it is kept in a fixed vessel called a font, so that the people may use it conveniently when entering or leaving. There is an indulgence of 100 days for using it. Water is the natural element for cleansing; and symbolically it denotes interior purification. It has been used in many religions. The laws of Moses enjoined the sprinkling of the people, the sacrifices, etc. In the Christian Church its use goes back probably to the 2century. Holy water is usually blessed just before the principal Mass on Sunday, but may be blessed at any other time. The priest reads several prayers, including an exorcism of the salt and the water, and puts the salt into the water in the form of a threefold cross, in the name of the three Persons of the Blessed Trinity. He then asks God's blessing on it.