In most cases, the wind was south for Blakelock. He knew a Dupré from a Diaz de la Peña, and both from a Ryder or an Inness. He had no trouble recognizing friends, let alone his wife, Cora. And perhaps unfortunately, he could tell a Blakelock from its imitations. Shown one of his own paintings, he knew not only that it was his, but also the conditions under which he had painted it, how much he was given for it and by whom, and what the critics who may have noticed it wrote in their reviews. I say "unfortunately" because his clarity of mind on artistic matters—and his remaining gifts as an artist—exposed him to one of the most extraordinary art scams I have ever read about.

The exploitationist was one "Mrs. Van Rensselaer Adams," a self-styled philanthropist too prepossessing in manner and appearance to be perceived as the con woman she was. Adams decided to pursue Blakelock after reading about the staggering sum Brook by Moonlight brought at auction. Twenty thousand dollars was big money in 1916, and money then, as now, made news. Adams persuaded the New York Tribune to send a cub reporter up to Middletown, New York, to interview the mad painter of masterpieces, and then she quickly took over Blakelock's life. The artist became Adams's ward, counted on to lay one golden egg after another, ostensibly for the benefit of his pauperized family, who didn't have the car fare to visit him. It is not a pretty story, though, in fairness to Adams, who once organized a benefit exhibition for the "Blakelock Fund," the artist lived better—and Adams a great deal better—than either would have without her efforts. But she was something of a dominatrix, abusing her ward when he turned out modernist works instead of the tried-and-true moonlit scenes. When the accounts were closed, the family received $184.07, after fees and expenses. Eventually, Adams herself went mad: She was found ranting about Blakelock outside his exhibition at the Grand Central Galleries, in late 1941.

Unlike Ryder, who was born the same year as he was and with whom he was often compared in the 1880s, Blakelock has not, in my view, altogether stood the test of time. This is partly due to the present material condition of his canvases. I recently visited the American wing of the Metropolitan Museum to see what of his was on view. There was one work, a large woods-and-water painting, with foliage silhouetted against moonlight. The picture must have seemed beautiful at one time, but now it is faded and even shabby, and I was not surprised that there was nothing else by him, if it was representative. It is a cruel thought, perhaps, but I would have been grateful to see the landscape banknotes, if they still exist. They were done too early to be counted Conceptual art, and I am doubtful Blakelock would have wanted them to be seen that way anyway. He was after visual poetry or, better, visual music.

The Unknown Night is an exceedingly readable book. Vincent's descriptions of old New York are marvelous (Blakelock's 1870 painting of the shanties on Fifty-fifth Street looks terrific), and the narrative of Blakelock's travels among the Indians in the lost world of the West is compelling (the paintings of Indians amid their tepees seem actually sweet). It is just the masterpieces that have gone dry. Nevertheless, this tale of madness, greed, fame, and sorrow is a cautionary account for those who look to art for happiness.

Arthur C. Danto is a contributing editor of Artforum and art critic for The Nation.