As a president of Standard Oil, Henry Folger made millions but borrowed constantly to buy rare books and relics related to Shakespeare. He and his wife Emily, whose Vassar Master’s thesis analyzed Shakespearean texts, lived frugally aside from the odd $50,000 or $35,000 shelled out for quartos or lutes. For the Folgers, Collecting Shakespeare (Johns Hopkins Univ., $29.95) was a passion. Henry began his collection in 1889 with a 1685 Fourth Folio; he spent $107.50. Eventually the couple behind D.C.’s Shakespeare Library acquired 92,000 books; eighty-two of these were First Folios, printed in 1623. But numbers tell only one story; Stephen H. Grant’s chronicle relates many others—as do those First Folios, each with its unique provenance and marginalia. In a plaint familiar to all bibliophiles, Folger lamented not having time to read his books; he pored over more auction catalogs than plays, and until the library was built in 1932, his acquisitions stayed in storage. But the Folgers always intended their collection to serve scholars, and if Henry died before he wrote his own book, his collection--“his gift to the nation”—has been invaluable for thousands of researchers.