Kiss, a familiar form of salutation by touching with the lips as an expression of respect or affection, in earlier times and still in many countries used in the common intercourse of man with man, but mostly limited by modern Englishmen to the domestic and dearer relationships of life. The osculum was a formal symbol of goodwill among the ancient Romans, and was adopted by the early Christians, whose 'holy kiss' and 'kiss of charity' carried the weight of apostolic sanction. The 'kiss of peace' at the mass, in the Eastern Church and the Mozarabic and Ambrosian liturgies, is given before the offertory and consecration; but in the Roman mass it follows the consecration and is closely connected with the communion. About the end of the 13th century the kiss of peace in the
West gave way to the osculatorium, called also the instrumentum or tabella pacis, pax, pacifical, or freda, a plate with a figure of Christ on the cross stamped on it, kissed first by the priest, then by the clerics and congregation. The kiss of peace was given also at baptism, and is still given by the other bishops to a bishop newly consecrated, and by the bishop to a priest at his ordination; and the Greeks still preserve the rite of giving the kiss of peace to the dead.
The Christians early adopted the practice of kissing the altar as a mark of reverence to the place on which the eucharist is offered, and the officiating priest still does so repeatedly in the Roman mass. It is usual also to kiss the golden cross of the sandal on the pope's right foot on his appointment to office, by newly-created cardinals and by persons on being granted an audience. Even royal persons in former times paid this act of homage to the Vicar of Christ; it is said that Charles V. was the last that did so.
See Kahle, De Osculo Sancto (Königsberg, 1867); Valentini, De Osculatione Pedum Romani Pontificis (Rome, 1588); and Pougard, Del Bacio de' Piedi de' Sommi Pontefici (Rome, 1807).