He made another effort, engaged a potter to assist him, giving the clothes off his own back to pay him, and afterwards receiving aid from a friendly neighbour, and this time proved that his mixture was of the right kind. But the furnace having been built with mortar which was full of flints, burst with the heat, and the splinters adhered to the pottery. Sooner than allow such imperfect specimens of his art to go forth to the world, Palissy destroyed them, "although some would have bought them at a mean price." Better days, however, were at hand for himself and family. His next efforts were successful. An introduction to the Duke of Montmorency procured him the patronage of that nobleman, as well as of the king. He now found profitable employment for himself and food for his family. "During the space of fifteen or sixteen years in all," he said afterwards, "I have blundered on at my business. When I had learned to guard against one danger, there came another on which I had not reckoned. All this caused me such labour and heaviness of spirit, that before I could render my enamels fusible at the same degrees of heat, I verily thought I should be at the door of my sepulchre.... But I have found nothing better than to observe the counsel of God, his edicts, statutes, and ordinances; and in regard to his will, I have seen that he has commanded his followers to eat bread by the labour of their bodies, and to multiply their talents which he has committed to them." When the Reformation came, Palissy was an earnest reformer, on Sunday mornings assembling a number of simple, unlearned men for religious worship, and exhorting them to good works. Court favour exempted him from edicts against Protestants, but could not shield him from popular prejudice. His workshops at Saintes were destroyed; and to save his life and preserve the art he had invented, the king called him to Paris as a servant of his own. Thus he escaped the massacre of St. Bartholomew. Besides being a skilful potter, Palissy was a naturalist of no little eminence. "I have had no other book than heaven and earth, which are open to all," he used to say; but he read the wondrous volume well, while others knew it chiefly at second-hand, and hence his superiority to most of the naturalists of the day. He was in the habit of lecturing to the learned men of the capital on natural history and chemistry. When more than eighty years of age he was accused of heresy, and shut up in the Bastille. The king, visiting him in prison, said, "My good man, if you do not renounce your views upon religious matters, I shall be constrained to leave you in the hands of my enemies." "Sire," replied Palissy, "those who constrain you, a king, can never have power over me, because I know how to die." Palissy died in prison, aged and exhausted, in 1590, at the age of eighty.