The manner of rendering the hands callous, or insensible, so that they may take up, and hold, ignited iron, charcoal, or other substances, may be seen in an English publication of 1667. The _Journal des Savants_, of 1677, contains the secret. "It consists in applying to the hands, various pastes, with spirits of sulphur, (sulphuric acid,) which destroys the epidermis, &c. and the nervous energy." This corroborates the account by Beckman. We read that Richardson had prepared his tongue in such a manner, that he could hold on the point of it a live coal, covering it first with pitch, rosin, and sulphur, and could hold a piece of ignited iron between his teeth. After showing the coal on his tongue, he would then extinguish it in his mouth. The _Mémoires de l'Académie_ state, that a person who is salivated can put a live coal in his mouth. The _Dictionnaire de l'Industrie_ observes, that the sulphur diminishes the heat of the coal, for the flame is less hot than a candle; and that the flame of a combination of pitch, rosin, and sulphur, is still less hot, and by no means so considerable as we would imagine. In the experiment, the rosin is not melted, and the flame of the sulphur is inconsiderable. M. Gallois observes, that he witnessed in the Swedish iron founderies, the men hold melted cast iron in their hands, doubtless having them previously prepared. The traces of this art may be found in the works of the ancients. A festival was held annually, on Mount Soracta, in Etruria, at which the Hirpi, who lived not far from Rome, jumped through burning coals, and on this account had certain privileges granted them by the Roman Senate. Women also, we are informed, were accustomed to walk over burning coals, at Cartabola, in Cappadocia, near the temple dedicated to Diana. Servius remarks, that the Hirpi did not trust to their sanctity so much as they did to the preparation of their feet for the operation!