How at the poles opposing Ethers dwell, Attract the quivering needle, or repel. How Gravitation by immortal laws Surrounding matter to a centre draws; 30 How Heat, pervading oceans, airs, and lands, With force uncheck'd the mighty mass expands; And last how born in elemental strife Beam'd the first spark, and lighten'd into Life. Now in sweet tones the inquiring Muse express'd Her ardent wish; and thus the Fair address'd. "Priestess of Nature! whose exploring sight Pierces the realms of Chaos and of Night; Of space unmeasured marks the first and last, Of endless time the present, future, past; 40 Immortal Guide! O, now with accents kind Give to my ear the progress of the Mind. How loves, and tastes, and sympathies commence From evanescent notices of sense? How from the yielding touch and rolling eyes The piles immense of human science rise?-- With mind gigantic steps the puny Elf, And weighs and measures all things but himself!" The indulgent Beauty hears the grateful Muse, Smiles on her pupil, and her task renews. 50 Attentive Nymphs in sparkling squadrons throng, And choral Virgins listen to the song; Pleased Fawns and Naiads crowd in silent rings, And hovering Cupids stretch their purple wings. II. "FIRST the new actions of the excited sense, Urged by appulses from without, commence; With these exertions pain or pleasure springs, And forms perceptions of external things. Thus, when illumined by the solar beams, Yon waving woods, green lawns, and sparkling streams, In one bright point by rays converging lie 61 Plann'd on the moving tablet of the eye; The mind obeys the silver goads of light, And IRRITATION moves the nerves of sight. [Footnote: _And Irritation moves_, l. 64. Irritation is an exertion or change of some extreme part of the sensorium residing in the muscles or organs of sense in consequence of the appulses of external bodies. The word perception includes both the action of the organ of sense in consequence of the impact of external objects and our attention to that action; that is, it expresses both the motion of the organ of sense, or idea, and the pain or pleasure that succeeds or accompanies it. Irritative ideas are those which are preceded by irritation, which is excited by objects external to the organs of sense: as the idea of that tree, which either I attend to, or which I shun in walking near it without attention. In the former case it is termed perception, in the latter it is termed simply an irritative idea.]