Instantaneous freezing: During frosty weather, let a vessel be half filled with water, cover it closely, and place it in the open air, in a situation where it will not experience any commotion; it will thereby frequently acquire a degree of cold more intense than that of ice, without being frozen. If the vessel, however, be agitated ever so little, or receive even a slight blow, the water will immediately freeze with a singular rapidity.
The cause of this phenomenon is, that water does not congeal unless its particles unite together, and assume among themselves a new arrangement. The colder the water becomes, the nearer its particles approach each other; and the fluid which keeps it in fusion gradually escapes; but the shaking of the vessel destroys the equilibrium, and the particles fall one upon another, uniting in a mass of ice.
Charcoal in sugar: The elements of sugar are carbon and water, as may be proved by the following experiment: Put into a glass a tablespoonful of powdered sugar, and mix it into a thin paste with a little water, and rather more than its bulk of sulphuric acid; stir the mixture together, the sugar will soon blacken, froth up, and shoot like a cauliflower out of the glass; and during the separation of the charcoal, a large quantity of steam will also be evolved.