 This meant that all who approached the altar were to be as pure as possible, and inevitably led to the exclusion of the laity from administering the Eucharist, reserving the practice to the clergy.It is difficult to say when the practice of offering the chalice to the people stopped, but it may be presumed that this was part of the way in which Church authorities sought to prevent anything disrespectful happening to the Eucharist; it was also, by this time, that Communion was given only on the tongue.This practice was challenged by the Bohemian reformer, Jacob of Mies, who in 1414 began to offer Communion under both kinds to his congregation.