It has been wisely said that failure to make use of the well-recognized means of clinical investigation leads to more errors in diagnosis than does ignorance. The laity sometimes neglect to take advantage of the wonderful discovery of Jenner, and we wonder at their apathy. What shall we say of the physician who, in so serious a matter as the diagnosis of phthisis, neglects to make use of the simple and beautiful staining methods of Koch? The typical consumptive is a deplorably familiar spectacle. The layman thinks that he can recognize the disease at sight, but let no physician make this mistake.
Of the 1400 patients supposed to be in the advanced stages of pulmonary tuberculosis and sent to the Cook County Hospital for Consumptives from the various hospitals and physicians of Cook county, 120, or 8.5 per cent., have proved, after thorough investigation and prolonged observation, to be non-tuberculous.