[From Dickens's Household Words.] THE MYSTERIES OF A TEA-KETTLE. At one of Mr. Bagges's small scientific tea-parties, Mr. Harry Wilkinson delivered to the worthy gentleman a lecture, based principally on reminiscences of the Royal Institution, and of a series of lectures delivered there by Professor Faraday, addressed to children and young people. For it is not the least of the merits of that famous chemist and great man, Professor Faraday, that he delights to make the mightiest subject clear to the simplest capacity, and that he shows his mastery of Nature in nothing more than in being thoroughly imbued with the spirit of her goodness and simplicity. This particular lecture was on Natural Philosophy in its bearings on a kettle. The entertainment of a "Night with Mr. Bagges" was usually extemporaneous. It was so on this occasion. The footman brought in the tea-kettle. "Does it boil?" demanded Mr. Bagges. "It have biled, sir," answered the domestic. "Have biled, sir!" repeated Mr. Bagges. "_Have_ biled! And what if it has 'biled,' or _boiled_, as I desire you will say in future? What is that to the purpose? Water may be frozen, you simpleton, notwithstanding it _has_ boiled. Was it boiling, sir, eh? when you took it off the fire? That is the question, sir." "Yes, sir, that was what I mean to say, sir," replied Thomas. "Mean to say, sir! Then why didn't you say it, sir? Eh? There--no, don't put it on, sir; hold it still. Harry, reach me the thermometer," said Mr. Bagges, putting on his spectacles. "Let me see. The boiling point of water is two hundred and--what?" "Two hundred and twelve, Fahrenheit," answered Master Wilkinson, "if commonly pure, and boiled in a metallic vessel, and under a pressure of the atmosphere amounting to fifteen pounds on every square inch of surface, or when the barometer stands at thirty inches." "Gracious, what a memory that boy has!" exclaimed his uncle. "Well; now this water in the kettle--eh?--why, this is not above one hundred and fifty degrees. There, sir, now set it on the fire, and don't bring me up cold water to make tea with again; or else," added Mr. Bagges, making a vague attempt at a joke, "or else--eh?--you will get yourself into hot water." Mr. Thomas was seized with a convulsion in the chest, which he checked by suddenly applying his open hand to his mouth, the effort distending his cheeks, and causing his eyes to protrude in a very ridiculous manner, while Mr. Bagges disguised his enjoyment of the effects of his wit in a cough. "Now let me see," said the old gentleman, musingly contemplating the vessel simmering on the fire; "how is it, eh, Harry, you said the other day that a kettle boils?" "La!" interrupted Mrs. Wilkinson, who was of the party, "why, of course, by the heat of the coals, and by blowing the fire, if it is not hot enough."