Yet not alone from humid skies we pine; For air may be too dry. The subtle heaven, 165 That winnows into dust the blasted downs, Bare and extended wide without a stream, Too fast imbibes th’ attenuated lymph Which, by the surface, from the blood exhales. The lungs grow rigid, and with toil essay 170 Their flexible vibrations; or inflam’d, Their tender ever-moving structure thaws. Spoil’d of its limpid vehicle, the blood A mass of lees remains, a drossy tide That slow as Lethe wanders thro’ the veins, 175 Unactive in the services of life, Unfit to lead its pitchy current thro’ The secret mazy channels of the brain. The melancholic fiend, (that worst despair Of physic) hence the rust-complexion’d man 180 Pursues, whose blood is dry, whose fibres gain Too stretch’d a tone: And hence in climes adust So sudden tumults seize the trembling nerves, And burning fevers glow with double rage. Fly, if you can, these violent extremes 185 Of air; the wholesome is nor moist nor dry. But as the power of chusing is deny’d To half mankind, a further task ensues; How best to mitigate these fell extreams, How breathe unhurt the withering element, 190 Or hazy atmosphere: Tho’ custom moulds To every clime the soft Promethean clay; And he who first the fogs of Essex breath’d (So kind is native air) may in the fens Of Essex from inveterate ills revive 195 At pure Montpelier or Bermuda caught. But if the raw and oozy heaven offend, Correct the soil, and dry the sources up Of watry exhalation; wide and deep Conduct your trenches thro’ the spouting bog; 200 Solicitous, with all your winding arts, Betray th’ unwilling lake into the stream; And weed the forest, and invoke the winds To break the toils where strangled vapours lie; Or thro’ the thickets send the crackling flames. 205 Mean time, at home with chearful fires dispel The humid air: And let your table smoke With solid roast or bak’d; or what the herds Of tamer breed supply; or what the wilds Yield to the toilsom pleasures of the chase. 210 Generous your wine, the boast of rip’ning years, But frugal be your cups; the languid frame, Vapid and sunk from yesterday’s debauch, Shrinks from the cold embrace of watry heavens. But neither these, nor all Apollo’s arts, 215 Disarm the dangers of the dropping sky, Unless with exercise and manly toil You brace your nerves, and spur the lagging blood. The fat’ning clime let all the sons of ease Avoid; if indolence would wish to live. 220 Go, yawn and loiter out the long slow year In fairer skies. If droughty regions parch