where first icicles are produced, which combine at angles of 60°, while others attach themselves to each vertex, until it all becomes ice; and so that, while this is going on, the water does not gradually become viscous, but is as perfectly fluid as if its temperature were far higher, although it is absolutely ice-cold.

The matter that disengages itself, which is dissipated suddenly at the moment of solidification, is a considerable quantum of caloric, the disappearance of which, as it was only required for preserving fluidity, leaves the new ice not in the least colder than the water which shortly before was fluid.

Many salts, and also rocks, of a crystalline figure, are produced thus from a species of earth dissolved in water, we do not exactly know how. Thus are formed the