From a very early in his career, Cades had been greatly admired for his drawings. Fluent in black and red chalk, pastel, pen, wash and watercolour, he was at heart as much a draughtsman as a painter, As a young artist in the early 1770’s he seems to have supported himself through the sale of his drawings, particularly those in imitation of the work of old masters. In later, more successful years he continued to produce highly finished drawings of original compositions, which were avidly collected by foreign visitors to Rome. Important groups of drawings by Cades are in the collections of the Museu Nacional de Arte Antiga in Lisbon, the Hermitage in St. Petersburg, the Kupferstichkabinett in Berlin and the Philadelphia Museum of Art.
This late drawing, previously unpublished, is likely to be such an independent work, as no related painting of this subject by the artist is known. In style and technique, the present sheet may be compared with other drawings by Cades of the 1790’s, such as a study of St. Nicholas of Bari Receiving His Bishop’s Robes in the Museu Nacional de Arte Antiga in Lisbon.
The subject of this drawing is taken from Greek mythology. Jupiter had seduced Io, the beautiful daughter of the first King of Argos and a priestess of the temple of Juno, the god’s wife. When Juno became suspicious, Jupiter quickly changed Io into a white heifer to hide her from his wife.