Aladdin's ring was a preservative against every evil Gundoforus. No one could pass with poison the gate of Gundoforus. Nourgehan's bracelet. When poison was present the stones of this bracelet seemed agitated. Opals turn pale at the approach of poison.
Peacocks ruffle their feathers at the sight of poison. Rhinoccros. If poison is put into a cup made of rhinoceros' horn, the liquid will effervesce. Sign of the Cross was supposed in the Middle Ages to be a poison detector.
Venetian glass will shiver at the approach of poison. (See also Philosopher's Egg.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894