Instructions letter from Diogo Horta, a merchant, to António de Melo,a solicitor.
The author tells the addressee which codes to adopt in order to tell him about his brother,using a comb and a rattle.
The New Christians Diogo da Horta and Fernão da Horta were arrested by the Inquisition on the charge of Judaism. Diogo da Horta was the first to be arrested. He wrote two letters on some pieces of fabric, one to his brother Fernão da Horta and another to a letter carrier who denounced him. This latter, António de Melo, told the court how Diogo da Horta managed to write in prison: he made the support from a towel of Indian fabric, the ink from vinegar and candle smoke, which he collected using a roof tile, and the pen from a broomstick. The brother was arrested later, precisely because of this correspondence.
