The stained glass window depicts St. John holding a chalice and out of the chalice is rising an unmistakable snake! Its position is such that it looks as if the snake has just bitten or will bite St. John’s hand.
This commemorates the testimony that once, while at Ephesus, John was given a cup of poisoned wine to drink. Before drinking, he blessed the cup and the poison departed the cup in the form of a serpent.
Old Christian Latin prayer and conclusion: around 950 AD.
‘My God, and Father and Son and Holy Spirit, to whom all things are subject, on whom every creature depends and to whom every power is subject, and whom (each) fears and dreads,
and (by whom) the serpent is stilled and the dragon flees, the viper (made) silent, and that toad, which is called Rubita, becomes numb with sleep,
the scorpion is destroyed, and the (venomous serpent) regulus is conquered, the (poisonous insect) spalagius works no harm, and all venemous and hitherto creeping ferocious creatures and noxious animals are made dark and all roots adverse to human health are dried up.
You, Lord, destroy this venomous poison, destroy its deadly operation and void the powers that are in it; and give to all those whom you have created in your sight, eyes that they may see, ears that they may hear, a heart that they may understand your greatness.’
And when he (John) had said this he armed all with the sign of the cross and drank all that was in the cup: through the sign of the holy cross and through you, Christ Jesus and God the father of all living, saviour of the world, in the unity of the Holy Spirit, through all things world without end, amen.