The nurse, therefore, should send in specimens frequently, every week or so, and should never be satisfied with a negative report. As we have said before, finding the bacilli is proof positive that the patient has tuberculosis, but not finding them is no proof to the contrary. Countless lives have been sacrificed by considering a negative return as evidence that the patient was not tuberculous. The nurse should carry in her satchel specimen bottles for collecting sputum. These bottles are provided by the Health Department. If the nurse has been called to a patient by the Federated Charities, or through some similar source, or if the patient is one whom she herself has discovered, she may send the specimen to the laboratory on her own initiative. But if the patient is already under the care of a physician who has not made a diagnosis, the nurse may call upon him and ask if she may take such a specimen to be examined. This courtesy will doubtless ensure better co-operation and understanding, but if the physician refuses, the nurse is then in an awkward position. In a short time she will learn the various physicians of her district, those whom she may call upon, and those whom she may not, and she will learn to exercise considerable discretion concerning them. Valuable as these sputum examinations may be in the case of a positive finding, they should never take the place of a careful physical examination. It is only when this examination is not to be had, when the diagnosis can be obtained in no other way, that the nurse will be obliged to rely upon sputum examinations alone in dealing with her patients. A positive sputum should confirm the diagnosis made by physical examination—it is not, or should not be, the only means of obtaining this diagnosis. Therefore, the fact that a Health Department is equipped to make sputum examinations should never for a moment supplant the dispensary, in charge of a specialist or expert. A specialist is able by auscultation, percussion, and an ear finely trained to detect changes in the breath sounds, and to recognize tuberculosis weeks before the diagnosis is confirmed by sputum findings. In this way it is possible to place a patient under treatment long in advance of the time when the average physician would have recognized the disease—an advantage to the patient and to the community as well.