Yet after all, and often in this very process of divulsion, we catch glimpses of a nobler sort of change, For there is a third species to which I might perhaps give the name of transforming: change. When, for example, a certain portion of oxygen and a certain portion of hydrogen, each having its own distinctive qualities, are brought into contact with one another, they utterly change. The qualities of both disappear, and a new set of qualities takes their place. The old ones are gone,--gone, but not lost; for they have been transformed into new ones of a predetermined and constant kind. Only a single sort of change is open to these elements when in each other's presence, and in precisely that way they will always change. In so changing they do not, it is true, fully keep their past; but a fixed relation to it they do keep, and under certain conditions may return to it again. The transforming changes of chemistry, then, are of a different nature from those of the mechanic destruction just described. In those the ruined organism leaves not a wrack behind. In chemic change something definite is held, something that originally was planned and can he prophesied. An end is attained: the fixed combination of just so much oxygen with just so much hydrogen for the making of the new substance, water. Here change is productive, and is not mere waste, as in organic destruction. Something, however, is lost--the old qualities; for these cannot be restored except through the disruption of the new substance, the water in which they are combined. VI