5. When there is combination, the bodies composing it lose their characteristic properties, whilst the composition resulting from it possesses new ones, different from those of the first. It is thus, for example, that oxygen and hydrogen, which are invisible gases, being chemically combined, form water, which is liquid, solid or vaporous according to temperature. Water, properly speaking, is no more oxygen and hydrogen, but a new body. This water decomposed, the two gases, becoming again free, recover their properties and are no more water. The same quantity of water can thus be decomposed and recomposed ad infinitum.