Mercury sent John Keats to an early grave The fatal moment came in September 1817. Keats was writing the third book of Endymion at Oxford. By the time he returned to his brothers in Hampstead, we know that he was dosing himself with mercury for an unspecified ailment - probably venereal disease. He continued to take mercury throughout the following winter and spring, and was still using it 10 months later, when he set off on his walking tour of Scotland in summer 1818. Back in London in August, a chronic sore throat, toothache, irritability and nervousness show us how Keats's protracted recourse to mercury had already poisoned him in body and mind - like the "pale warriors" of "La Belle Dame sans Merci," loitering disconsolately between life and death. In this vulnerable state he was confined for three stressful months with his dying brother, contracting the tuberculosis that set him on the road to an early grave. With Keats already poisoned by mercury, the TB made rapid and fatal progress. A series of major haemorrhages followed early in 1820. It was now that Keats allowed doctors repeatedly to bleed pints of blood from his arms, weakening him further and often leaving him barely conscious. It was a treatment that he knew was useless, and so dangerous that it had put him off a medical career back in 1817. Increasingly convinced that there was, as he said, a "core of disease" within him, he painfully blistered his skin in the hope of drawing out whatever inner poison was sapping his health. Keats recognised his own symptoms. He had seen his brother - and countless others - die of consumption. Yet he allowed doctors to administer the old, hopeless panaceas for a disease that he knew was incurable. As he gradually sank lower over the summer of 1820, further physically shattering medications were administered - probably more mercury and the emetic aloe vera - producing the violent fits of anger, despondency and jealousy in the harrowing letters he wrote to Fanny Brawne at this time. With his imminent departure for Italy, Fanny noticed how short and thin Keats's hair had become, and tenderly lined his travelling cap with silk to keep his bare head warm. Loss of hair is not a result of pulmonary consumption. It is, however, a well-known consequence of mercury poisoning, as is destruction of the lining of the stomach. When Keats arrived in Rome, ostensibly to find a mild winter for his sickly lungs, he placed himself in the care of the physician James Clark. Having secured accommodation for the poet in the Piazza di Spagna - the city quarter most approved for consumptive patients - Clark quickly concluded that Keats's disease was not in fact in his lungs, but his stomach, and reduced his diet accordingly. Joseph Severn, the painter and Keats's companion, recorded the agonies of hunger the poet suffered as a consequence. Clark had decided that Keats needed treatment for one of the effects of mercury poisoning, not consumption - a decision that, of course, made no difference to the tragic outcome of the poet's sojourn in Rome. Keats has lived a long posthumous existence as the most famous literary victim of tuberculosis, and tuberculosis was indeed the immediate agent of his early demise. It was the effects of mercury poisoning, however, that were responsible for him contracting the disease in the first place, while incarcerated with his sick brother and wounded by a lacerating review. So Lord Byron almost got it right - except that criticism, even in the Quarterly Review, was never so killing. It was prolonged doses of mercury, self-administered, that had in reality "snuff'd out" the bright star of English poetry. Professor Nicholas Roe's new biography, 'John Keats', is published by YUP