The author of the Prometheus Unbound (to take an individual instance of the last character) has a fire in his eye, a fever in his blood, a maggot in his brain, a hectic flutter in his speech, which mark out the philosophic fanatic. He is sanguine-complexioned, and shrill-voiced. As is often observable in the case of religious enthusiasts, there is a slenderness of constitutional _stamina_, which renders the flesh no match for the spirit. His bending, flexible form appears to take no strong hold of things, does not grapple with the world about him, but slides from it like a river— ‘And in its liquid texture mortal wound Receives no more than can the fluid air.’ The shock of accident, the weight of authority make no impression on his opinions, which retire like a feather, or rise from the encounter unhurt, through their own buoyancy. He is clogged by no dull system of realities, no earth-bound feelings, no rooted prejudices, by nothing that belongs to the mighty trunk and hard husk of nature and habit, but is drawn up by irresistible levity to the regions of mere speculation and fancy, to the sphere of air and fire, where his delighted spirit floats in ‘seas of pearl and clouds of amber.’ There is no _caput mortuum_ of worn-out, thread-bare experience to serve as ballast to his mind; it is all volatile intellectual salt of tartar, that refuses to combine its evanescent, inflammable essence with any thing solid or any thing lasting. Bubbles are to him the only realities:—touch them, and they vanish. Curiosity is the only proper category of his mind, and though a man in knowledge, he is a child in feeling. Hence he puts every thing into a metaphysical crucible to judge of it himself and exhibit it to others as a subject of interesting experiment, without first making it over to the ordeal of his common sense or trying it on his heart. This faculty of speculating at random on all questions may in its overgrown and uninformed state do much mischief without intending it, like an overgrown child with the power of a man. Mr. Shelley has been accused of vanity—I think he is chargeable with extreme levity; but this levity is so great, that I do not believe he is sensible of its consequences. He strives to overturn all established creeds and systems: but this is in him an effect of constitution. He runs before the most extravagant opinions, but this is because he is held back by none of the merely mechanical checks of sympathy and habit. He tampers with all sorts of obnoxious subjects, but it is less because he is gratified with the rankness of the taint, than captivated with the intellectual phosphoric light they emit. It would seem that he wished not so much to convince or inform as to shock the public by the tenor of his productions, but I suspect he is more intent upon startling himself with his electrical experiments in morals and philosophy; and though they may