The purity of water is now felt to be among the foremost necessities of life. It is one which asks nothing from us except to refrain from polluting what comes from heaven so limpid. And yet we are half satisfied to go on habitually inflicting on ourselves a plague more foul and noxious than any occasional turning of our rivers into blood. The two plagues which dealt with minute forms of life may well remind us of the vast part which we are now aware that the smallest organisms play in the economy of life, as the agents of the Creator. Who gives thanks aright for the cheap blessing of the unstained light of heaven? But we are insensible to the every-day teaching of this narrative: we turn our rivers into fluid poison; we spread all around us deleterious influences, which breed by minute forms of parasitical life the germs of cruel disease; we load the atmosphere with fumes which slay our cattle with periodical distempers, and are deadlier to vegetation than the hail-storm or the locust; we charge it with carbon so dense that multitudes have forgotten that the sky is blue, and on our Metropolis comes down at frequent intervals the darkness of the ninth plague, and all the time we fail to see that God, Who enacts and enforces every law of nature, does really plague us whenever these outraged laws avenge themselves. The miraculous use of nature in special emergencies is such as to show the Hand which regularly wields its powers. At the same time there is no more excuse for the rationalism which would reduce the calamities of Egypt to a coincidence, than for explaining away the manna which fed a nation during its wanderings by the drug which is gathered, in scanty morsels, upon the acacia tree. The awful severity of the judgments, the series which they formed, their advent and removal at the menace and the prayer of Moses, are considerations which make such a theory absurd. The older scepticism, which supposed Moses to have taken advantage of some epidemic, to have learned in the wilderness the fords of the Red Sea,[12] to have discovered water, when the caravan was perishing of thirst, by his knowledge of the habits of wild beasts, and finally to have dazzled the nation at Horeb with some kind of fireworks, is itself almost a miracle in its violation of the laws of mind. The concurrence of countless favourable accidents and strange resources of leadership is like the chance arrangement of a printer’s type to make a poem.