The word metamorphosis usually conjures the image of a caterpillar in its cocoon, converting itself into a moth or a butterfly. But a different image came to me when I visited this exhibition on the writer Jill Johnston’s transfiguration from an analytic dance critic into a radical, lyrical, mostly autobiographical essayist covering the avant-garde performance scene of the 1960s and ’70s, with a focus on lesbian separatism and its role in women’s liberation. Strange as it may seem, I pictured a childhood science experiment in which I immersed an egg in vinegar, which melted its shell, leaving