It would be easy to extend these instances, in connexion with the phenomena of the globe, but the present will suffice to show that a little knowledge of natural science is an antidote to many superstitions. We proceed now to illustrations of agencies in active operation of a different character.
CHAPTER V.
Chemical wonders—Ice obtained in a red-hot vessel—The corpse candles of Wales—Luminous appearances after death—Sadoomeh the magician—The laughing gas—Sulphuric ether—Chloroform—Gunpowder compared with gun-cotton.
The word chemistry is, probably, derived from a Coptic root, signifying obscure or secret; and the German word geheim is traced to the same origin. The objects of this department of science are, to investigate the nature and properties of the elements of matter and their mutual actions and combinations; to ascertain the proportions in which they unite and the modes of separating them when united; and to inquire into the laws which affect and rule these agencies. A few of the wonders connected with this science may, therefore, appropriately follow the terrestrial phenomena which have just been considered.
The Romish church has rendered chemistry available in connexion with one of its prodigies, the so-called blood of St. Januarius. A substance is shown to the deluded worshippers in a phial, appearing in a congealed state; but, as masses are performed by the priests, it becomes fluid. The illusion practised in this case may, however, be easily effected by reddening sulphuric ether with orchanet, the onosma of Linnæus, and then saturating the tincture with spermaceti. This preparation is solid at ten degrees above the freezing point, and melts and boils at twenty degrees. Let the phial which contains it when coagulated, be held in the hand for a few minutes, and the temperature of the substance rises, and it becomes fluid. Even the warmth of a public assembly is sufficient for this purpose.
Marcus, the chief of one of the sects in the second century, who wished to amalgamate with Christianity the doctrines and rules of pagan rites, filled with white wine three cups of transparent glass; and, while he was praying, the liquid in one of the cups became like blood; in another, of a purple colour; and in the third, sky-blue. But these effects might easily be produced by chemical action. Professor Beyruss, at the court of the duke of Brunswick, promised that his white dress should become red during a repast; and the change took place, to the astonishment of the prince and his guests. M. Vogel, who relates this fact, does not reveal the means employed; but observes that, by pouring lime-water on the juice of beet-root, a colourless liquid is obtained, that a piece of cloth dipped in it and quickly dried becomes red in a few hours by the contact of the air alone; and that this effect may be accelerated in a room where champagne and other beverages charged with carbonic acid gas are abundantly used. Still more rapidly might the chance be effected in some temple, in the midst of rising incense and burning torches; and the veil which covered things deemed sacred, might thus have been seen to change from white to the colour of blood—a presage of fearful disasters.
A series of remarkable experiments was performed by professor Boutigny, at the British Association at Cambridge, in 1845. He commenced by showing, that when cold water is poured on a hot metallic surface, the heat is not communicated to it; and that the water assumes a spheroidal form, and continues to roll about, upheld at a minute distance from the heated surface, without boiling. The water was poured into a hot platinum cup kept in rapid motion, and resembled a small globe of glass dancing about. There was no hissing noise nor appearance of steam, though the globule of water must, nevertheless, have evaporated rapidly; for, after gradually diminishing in size, in the course of about two minutes it disappeared. The same result takes place when any substance capable of assuming a globular form is placed on a heated surface. In proof of this, the professor placed in the heated cup of platinum, iodine, ammonia, and some inflammable substances; each of which became globular, and danced about like the globule of water, but without emitting smell or vapour, or being inflamed, until the platinum cup was cooled.
Another experiment was yet more curious. Professor Boutigny heated a silver weight, of the same shape as the weight of a clock, until it was red-hot, and then lowered it by a wire into a glass of cold water, without there being any more indication of action in the water than if the weight had been quite cold. Professor Boutigny advanced no theory to account for these peculiar actions, further than that a film of vapour intervenes between the heated body and the substance, which prevents the communication of heat. The facts, however, he thought were of importance in a practical point of view, both as regards the tempering of metals, and in the explanation of the causes of steam-boiler explosions. It would seem, from experiments in tempering metals, that, if the metal be too much heated, the effect of plunging it into water will be diminished. In steam-boilers, also, if the heated water be introduced into a heated surface, the heat may not be communicated to the water, and the boiler may become red-hot, and without any great emission of steam; until, at length, when the boiler cools, a vast quantity of steam would become suddenly generated and the boiler burst.
The last and most curious experiment performed by professor Boutigny, was the freezing of water in a red-hot vessel. Having heated a platinum cup red-hot, he poured into it a small quantity of water, which was kept in a globular form, as in the other experiments. He then poured into the cup some liquid sulphurous acid; when a sudden evaporation ensued, and, on quickly inverting the cup, there came out a small mass of ice. The principle of this experiment, which called forth loud and continued applause, is this:—sulphurous acid has the property of boiling water when it is at a temperature below the freezing point; and, when poured into the heated vessel, the suddenness of the evaporation occasions a degree of cold sufficient to freeze water.
Liquid carbonic acid takes a high position for its freezing qualities. Mr. Adams, of Kensington, manufactures this curious liquid as an article of commerce, and has, occasionally, as much as nine gallons of it in store. In drawing it from its powerful reservoirs, it evaporates so rapidly as to freeze, and it is then a light porous mass, like snow. If a small quantity of this is drenched with ether, the degree of cold produced is even more intolerable to the touch than boiling water; a drop or two of the mixture producing blisters, just as if the skin had been burned! Mr. Adams states that, in eight minutes he has frozen a mass of mercury weighing ten pounds.