Until she was close to 40 Dorothea Dix (1802-1887) was a New England schoolteacher, writer of children's books, a part of no movement, neither an abolitionist nor a suffragette. Then on a visit to a Massachusetts jail she discovered the mission that would, for the rest of her life, take her across America and on international travels as the chief advocate for the humane treatment of the insane. She was also a prime mover in the whole area of penal reform and during the Civil War she became Superintendent of U.S. Army Nurses. At the time of her death she was called ""the most useful and distinguished woman America has yet produced."" She sought no personal publicity, shunned interviews, but went about her work methodically and with all the determination of the true zealot. Fortunately she had influential friends--as well as the facts and a manner that conservative legislators could not fault. Even the author, however, who is nothing if not an admiring biographer, softly suggests that the very qualities--""puritanical piety, spartan discipline, perfection in manner, inflexible dignity""--which propelled Miss Dix forward also accounted for the antagonisms she aroused in other women who wanted to help during the Civil War. Dix had no time to waste; her health was precarious, her tasks were prodigious, and there were improvements to be made wherever she cast her eye. Dorothy Clarke Wilson, well known for numerous biographies and novels, deserves high marks for her able and meticulous research. But readers looking for greater penetration and flair may well be put off by the dowdy style.