While Benvenuto Cellini (1500-1571), the unrivalled goldsmith, was imprisoned in Rome, in 1538, he strongly suspected that his enemies were seeking to poison him by tampering with his food. Cellini shared the belief of his contemporaries that there was no more deadly poison than diamond dust. One day, while eating his noonday meal, he felt something grate between his teeth. He paid no particular attention to this, but when he had finished eating his eye was caught by some bright particles on the plate. Picking up one of these and examining it carefully, he was terrified to find what he supposed to be a diamond splinter, and he straightway gave himself up for lost, thinking that he had swallowed a quantity of diamond dust. He prayed to God for an hour and finally became reconciled to the thought of dying, but suddenly it occurred to him that he had not tested the hardness of the fragment he had found in his food. He immediately took the splinter and tried to crush it between his knife and the stone window-sill; to his joy the attempt succeeded, and he became convinced that what he had swallowed was not diamond dust. Later, after his release, Cellini learned that an enemy had given a diamond to a certain Lione Aretino, a gem-cutter, instructing him to grind it up so that the dust could be placed in Cellini’s food. The gem-cutter was very poor and the diamond was worth a hundred scudi, so the man yielded to temptation and substituted a citrine for the diamond. To this circumstance alone did Cellini attribute his escape from death.[225] In England, more than seventy years after Cellini’s experience, diamond dust was selected as a poison to do away with a luckless prisoner. Sir Thomas Overbury had incurred the bitter animosity of the Countess of Essex, because he opposed her marriage with the favorite of James I, Robert Carr, Viscount Somerset, whom he had befriended and whose career he had furthered. The marriage took place, however, and, in 1613, Overbury was imprisoned in the Tower, through the machinations of the countess. She then sought the aid of one James Franklin, an apothecary, directing him to concoct a slow and deadly poison, which should be mixed with Overbury’s food. In the minutes of Franklin’s confession, he is said to have stated that the countess asked him what he thought of white arsenic. His reply was that this poison would prove too violent. “What say you (quoth she) to powder of diamonds?” He answered, “I know not the nature of that.” She said that he was a fool, and gave him pieces of gold, and bade him buy some of that powder for her. It appears, however, from the testimony, that a number of ingredients were employed, quite probably small doses of mercury, cantharides, etc., as well as the baleful diamond dust. Poor Overbury lingered on for more than three months, but was finally put out of his misery by a clyster of corrosive sublimate.[226]