Dr. John Croghan’s original interest in Mammoth Cave began when be read, in the journals of the day, accounts of the preservative qualities of the cave – how the timbers from the old nitre mine, now more than 30 years old, had not even begun to rot; how the bodies of dead bats, and even the bodies of Indians which had been found in the cave, remained perfectly intact and undecayed. The agent, the doctor surmised, must be the cave air. His interest intensified after his brother Nicholas visited the cave, and in 1839 he purchased it from Franklin Gorin for $10,000, slaves and all.
Dr. Croghan specialized in "pulmonary consumption" – known today as tuberculosis – and had 16 patients in his care in the winter of 1842-1843. As no cure or effective treatment had yet been found for tuberculosis, their grave condition seemed to Croghan to call for desperate measures. He sent his slaves into the cave to construct a series of buildings, along Main Cave near the Star Chamber, two of stone and eight of wood, to function as a sanitarium where his patients could "take the airs." Other huts were built at Wandering Willie’s Spring, Audubon Avenue, and Pensico Avenue. Croghan led his patients into the cave, to their new residence, and there they remained for some weeks.
Tours would pass a bizarre scene. Pale, spectral figures in dressing-gowns moved weakly along the passageway, slipping in and out of shadowed huts, the silence of the cave broken by hollow coughing and muttered conversations. Withered bushes could be found by the pathside, the failed attempts to bring living plants to cheer the surroundings.
At first, the patients claimed to be much improved. Dr. Croghan, anticipating success, began to draw up plans for a hotel to be built inside the cave at the Cross-Rooms (now called Wright’s Rotunda) to house all those who were bound to come when the word spread, and a stagecoach route into the cave to bring them inside in comfort.
But as time passed it became obvious that the patients’ claims of improvement came only from an improved morale. The smoke of cooking and heating fires, and the coolness and clamminess of the cave air began to ravage lungs already weakened by disease. In time, some of the patients began to ask to return to the surface, but Dr. Croghan persuaded them to remain, for the sake of their health. Only Oliver H. P. Anderson departed – and by then the deaths had begun.
In all, five patients perished underground, their bodies laid out on the long, flat stone now called Corpse Rock. Admitting, at last, that the experiment had failed, Dr. Croghan brought the surviving patients to the surface, where they met their ends in the normal course of their disease.
Dr. Croghan himself would struggle against tuberculosis for only six more years before it would launch a personal attack on the doctor, and claim his life in 1849. His will would grant ownership of the cave to his seven nieces and nephews, the "Croghan heirs," and would remain in that family until the 1920s.