The genius of William Blake, steeped in Hebraism, never showed greater power than in his picture of Plague. A gigantic hideous form, pale-green, with the slime of stagnant pools, reeking with vegetable decays and gangrene, the face livid with the motley tints of pallor and putrescence, strides onward with extended arms like a sower sowing his seeds, only in this case the germs of his horrible harvest are not cast from the hands, but emanate from the fingers as being of their essence. Such, to the savage mind, was the embodiment of malaria, sultriness, rottenness, the putrid Pretraya, invisible, but smelt and felt. Such, to the ignorant imagination, is the Destroying Angel to which rationalistic artists and poets have tried to add wings and majesty; but which in the popular mind was no doubt pictured more like this form found at Ostia (fig. 16), and now passing in the Vatican for a Satan,--probably a demon of the Pontine Marshes, and of the fever that still has victims of its fatal cup (p. 291). In these fearful forms the poor savage believed with such an intensity that he was able to shape the brain of man to his phantasy; bringing about the anomaly that the great reformer, Luther, should affirm, even while fighting superstition, that a Christian ought to know that he lives in the midst of devils, and that the devil is nearer to him than his coat or his shirt. The devils, he tells us, are all around us, and are at every moment seeking to ensnare our lives, salvation, and happiness. There are many of them in the woods, waters, deserts, and in damp muddy places, for the purpose of doing folk a mischief. They also house in the dense black clouds, and send storms, hail, thunder and lightning, and poison the air with their infernal stench. In one place, Luther tells us that the devil has more vessels and boxes full of poison, with which he kills people, than all the apothecaries in the whole world. He sends all plagues and diseases among men. We may be sure that when any one dies of the pestilence, is drowned, or drops suddenly dead, the devil does it. Knowing nothing of Zoology, the primitive man easily falls into the belief that his cattle--the means of life--may be the subjects of sorcery. Jesus sending devils into a herd of swine may have become by artificial process a divine benefactor in the eye of Christendom, but the myth makes Him bear an exact resemblance to the dangerous sorcerer that fills the savage mind with dread. It is probable that the covetous eye denounced in the decalogue means the evil eye, which was supposed to blight an object intensely desired but not to be obtained.