At the end of his career, Ingres brought together 25 nude women in a painting he prepared with great care. The study of the painter’s extensive archives in Montauban, along with laboratory analysis, now makes it possible to reconstruct the history of a work that inspired as much fascination—among artists such as Picasso and Man Ray—as it did repulsion in Paul Claudel, who saw in The Turkish Bath “a pancake of maggots.”