Much surprise has sometimes been awakened by an apparent insensibility to intense heat. An instance of this occurred when a rivalry existed between the Augustine friars and the Jesuits. The father-general of the Augustine friars was dining with the Jesuits; and, when the table was removed, he entered into a formal discourse of the superiority of the monastic order, and charged the Jesuits with assuming the title of “fratres,” while they held not the three vows which other monks were obliged to consider sacred and binding. The general of the Augustine friars was very eloquent and very authoritative—and the superior of the Jesuits was very unlearned.
The Jesuit avoided entering the lists of controversy with the Augustine friar, but arrested his triumph by asking him if he would see one of his friars, who pretended to be nothing more than a Jesuit, and one of the Augustine friars who religiously performed the three vows, show instantly which of them would be readier to obey his superior?
The Augustine friar consented. The Jesuit then turning to one of his brothers, the friar Mark, who was waiting upon them, said, “Brother Mark, our companions are cold; I command you, in virtue of the holy obedience you have sworn to me, to bring here, instantly, out of the kitchen-fire, and in your hands, some burning coals, that they may warm themselves over your hands.” Father Mark instantly obeyed; and, to the astonishment of the Augustine friar, brought in his hands a supply of red burning coals, and held them to whoever chose to warm himself; and, at the command of his superior, returned them to the kitchen hearth. The general of the Augustine friars, with the rest of his brotherhood, stood amazed; he looked wistfully on one of his monks, as if he wished to command him to do the like. But the Augustine monk, who perfectly understood him, and saw this was not a time to hesitate, observed, “Reverend father, forbear, and do not command me to tempt God: I am ready to fetch you fire in a chaffing-dish, but not in my bare hands.” The triumph of the Jesuits was complete, and it is not necessary to add, that “the miracle” was noised about, and that the Augustine friars could never account for it, notwithstanding their strict performance of the three vows! And yet here was no mystery. According to sir James Mackintosh, “In the Mercure de France, there is a very curious account of experiments made at Naples to discover the means by which jugglers have appeared to be incombustible. They seem to be completely discovered, and chiefly to consist in, first, gradually habituating the skin, the mouth, throat, and stomach, to great degrees of heat; second, in rubbing the skin with hard soap, and in covering the tongue with hard soap, and over that with a layer of powdered sugar. By these means, the professor at Naples is enabled to walk over burning coals, to take into his mouth boiling oil, and to wash his hands in melted lead. The miracles of several saints, the numerous escapes from the fiery ordeal, and tricks now played by the Hindoo jugglers, are thus perfectly explained; and all these prodigies may be performed in a fortnight by any apothecary’s apprentice.”
Other instances of endurance are merely pretended. In country places, a conjurer sometimes appears in the streets, professing that he is able to eat fire; and yet he only rolls together a ball of flax or hemp, lights it, rolls round it some more of the same material, slips it cunningly into his mouth, and breathes through it to revive the flame; and so long as he inspires the air through the nostrils, and not through the mouth, he suffers no injury. A performer, named Richardson, in the seventeenth century, pretended to pour melted lead upon his tongue; but it is probable that he used the fusible metal formed of bismuth, tin, and lead, which melts at a low temperature, and which the writer has seen fused on a card, and poured into the hand with impunity by a person accustomed to handle hot substances.
Not many years ago, a man named Chaubert professed to be incombustible; but it has been proved that the human body is capable of bearing a very high degree of heat. Men of unquestionable integrity have surpassed all his wonders. Sir Charles Blagden exposed himself in a heated room where the heat was one or two degrees above 260°, and remained eight minutes in this situation. Eggs and a beef-steak were placed on a tin frame, near the thermometer, and in the space of twenty minutes the eggs were roasted quite hard, and in forty-seven minutes the steak was not only dressed, but almost dry. Another beef-steak, similarly placed, was rather over-done in thirty-three minutes. Chantrey, the celebrated sculptor, accompanied by five or six friends, also entered a furnace, and, after remaining two minutes, brought out a thermometer which stood at 320°. Some pain was experienced in this experiment, but it placed beyond all doubt that the human body has a remarkable power of enduring heat. Chaubert excited much wonder by taking phosphorus into his mouth; but, as that substance, when deprived of air, will not burn, he always closed his lips, and retired to eject the phosphorus immediately afterwards.
We turn now from the resistance of heat by chemical means, to some striking examples of its power.
The name of the Giants’ Causeway arose, probably, from an idea of the supernatural power, entertained in times of ignorance and superstition. And yet it is demonstrated that vast masses of rock are to be traced to causes strictly natural. Basalt is of very frequent occurrence on the surface of the globe, and is frequently detected in a variety of volcanoes, both extinct and active. The greatest mass of basalt hitherto observed is that in the Deccan, which constitutes the surface of many thousand square miles of that part of India. In other instances, it occurs in horizontal tabular masses, and is columnar. Sometimes, the basaltic columns are curved, and of this there is a beautiful example in the island of Staffa. Now basalt is not a crystalline substance, for as it is not capable, as all crystals are, of cleavage in the line of its planes, or at some angle with them, it is concretional. Its structure resembles an onion, or any bulbous root, for, in the centre, is a solid mass, about which are others just like the parts of the vegetable products already mentioned. These portions of basalt are at first of an oval form, and then they gradually become rudely hexagonal. Some non-columnar basalts show no trace of any particular arrangement of parts, while others have a globular structure, so that when the rock becomes much decomposed, it has the appearance of numerous bomb-shells and cannon-balls cemented together.
Here, then, we have an extraordinary effect of heat. Mr. Gregory Watt took seven hundred weight of the substance named rowley rag, kept it in fusion more than six hours, and cooled it so gradually, that eight days elapsed before it was taken from the furnace. The shape of the mass was uneven and while the thinner portion was, in consequence of more rapid cooling, vitreous, the thicker was stony; the one state passing into the other. Numerous spheroids were also formed, some being two inches in diameter. They were radiated with distinct fibres, the latter also forming concentric coats, when circumstances were favourable to such an arrangement. When the temperature had been sufficiently continued, the centres of the spheroids became compacted before they had attained the diameter of half-an-inch. When two spheroids came into contact, no penetration ensued; but the two bodies became mutually compressed and separated by a plane, well defined, and invested with a rusty colour. When several met, they formed prisms. In reasoning on these facts, Mr. G. Watt observes: “In a stratum composed of an indefinite number in superficial extent, but only one in height, of impenetrable spheroids, if their peripheries should come in contact in the same plane, it seems obvious that their mutual action would form them into hexagons; and if these were resisted below, and there was no opposing cause above them, it seems equally clear that they would extend their dimensions upwards, and thus form hexagonal prisms, whose length might be indefinitely greater than their diameters.”
That the great power in operation in the formation of basaltic columns is heat, appears to be indisputable. There is, for example, a bed of sandstone in furnaces for smelting metals, and, in the course of time, it requires to be repaired. Portions, taken out, on such occasions, have been found to have a columnar appearance: the heat of the furnace having changed the form of the substance, not by any fusion of its parts, but by a peculiar arrangement of them, thus giving them the specified figure.
Another astonishing result of this natural power is seen in the eruption of a volcano. The eye of a traveller, perhaps, as it is turned towards Vesuvius, discerns a dark red spot on the mountain’s side, issuing from an orifice near to the crater. But soon, that deep burning light apparently spreads out, or flows on into a long wide stream, descends the entire length of the great cone, and reaches to the plain below. But, as the first light was seen through and behind the mists which follow the departure of the sun, so now its extended influence is only rendered visible by the increasing gloom. But, as the eye is still attracted towards this remarkable eminence, a pillar of fire is seen rising up from the crater high into the air; while innumerable lights appear, like so many natural fire-works rushing upwards, and falling in a glowing shower, on the outer sides of the crater, which soon present the aspect of a heap of fire. Large and red-hot stones are flung forth from time to time, from the same troubled source, to fall, roll down the sides of the crater, and lose their brightness.