Great was his faith in this substance, as is apparent from his own words: "Oh, indescribable mixture, incomparable elixir, antidote beyond all praise! Celestial purgative (if I may be permitted to use the expression), which throws into the shade every medical prescription; which surpasses in fragrance every earthly aroma, and is more powerful than all essences; which purges the body like the juice of scammony, clears the lungs like hyssop, and the head like sneezewort; which not only cures the ailing limbs, but also, and this is much more valuable, washes off the stains from the conscience!"[168:2] Chrysostom (350-407) commented on the fact of the whole world's streaming to the site of Christ's crucifixion. Rome was also a favorite resort of pilgrims, chiefly as the site of the graves of the great apostles, while many flocked to the tomb of Saint Martin of Tours. Meanwhile, wrote Henry C. Sheldon in a "History of the Christian Church," there were emphatic cautions against an overestimate of the value of pilgrimages. The eminent Greek Father, Gregory of Nyssa (332-398), said that change of place brings God no nearer. The cult of relics developed rapidly in the Middle Ages. Even the theft of these precious objects, we are told, was condoned, "in virtue of the benevolent intent of the thief to benefit the region to which the treasure was conveyed."[169:1] The custom received encouragement from many eminent scholars, who appear to have been deceived by certain mysterious physical phenomena, the nature of which was not understood even in comparatively recent times.[169:2] Pope Gregory the First (550-604), we are told, was wont to bestow, as a mark of his special favor, presents of keys, in which had been worked up some filings of Saint Peter's chains, accompanied with a prayer that what had bound the apostle for martyrdom, might release the recipient from his sins. The second Nicene Council (A. D. 787) decreed that no church should be consecrated unless it enshrined some relics.[170:1] At the celebrated Benedictine abbey of Monte Cassino, in southern Italy, which was founded in the year 529, the care of the sick was enjoined as a pious obligation. There diseases were treated chiefly by means of prayers and conjurations, and by the exposition and application of sacred relics, which appealed to the patients' imagination, and thereby, through suggestion, assisted the healing forces of nature.[170:2] Thomas Dudley Fosbroke, in "British Monachism," states that among the early monks of England, medical practice devolved on clerks, on account of their ability to read Latin treatises on therapeutics. Until the middle of the fifteenth century, physicians were forbidden to marry, owing to the prevalent opinion that the father of a family could not heal so well as a bachelor. The art of writing prescriptions was made to conform to the dogmas of the existing religion, "for which reason relics were introduced into the Materia Medica."