A new book «Hothouse» (Simon & Schuster), by Boris Kachka takes as a given that its subject, Farrar, Straus&Giroux, has been and remains a great publisher, and without any question that’s the case. FSG, as it’s generally called, has brought us more than half a century of distinguished books, rarely slipping below the level of distinction it hoped to achieve. How it did so is certainly worth both parsing and paying tribute to, but a degree of disillusionment with this project sets in when we get past the cute title to the even cuter and more hyperbolic subtitle: «The Art