For forty years E. B. White's casual, concentrated thoughts have been entering our stream of consciousness. A coon descends a tree outside his window, and touches a hind foot down as cautiously ""as though this were the first contact ever made by a mammal with the flat world."" He empties an apartment of its ""indestructible keepsakes,"" and ponders nonconformity--on whose account ""no one should be made to feel uncomfortable or unsafe"" (this, apropos of public school prayer). The Maine of One Man's Meat and other memoirs yields ""The Death of a Pig""; once a separate volume and now, to White, a memento, ""This Is New York"" has not lost its nudging charm, as ""From the next booth drifts the conversation of radio executives; from the green salad come the little taste of garlic."" He is a noticing man, careful with words, daring with phrases. A roving, settling eye. At the 1939 New York World's Fair, young David Wagstaff wins a long-distance phone call--and when his father isn't home, gamely talks away to ""the invisible and infinitely surprised Mr. Henry."" So, impeccably, is immortality conferred. Long before it became fashionable, White had a countryman's suspicion of rampant growth; his literary appreciations extend to the St. Nicholas League and Don Marquis. For there is this: whether on an early steamer trip to Alaska--when White descends upward (as he sees it) from first-class passenger to night saloonman to firemen's messboy--or, lately, spending a Christmas in Florida beside three potted palms under a ""holy mobile"" star, he is--like his godson Stuart Little--""essentially cheerful and ready for anything."" What to do when flight palls: re-read E. B. White.