IN CASES of pulmonary tuberculosis there is no practical method of classifying the types of disease before treatment is begun. After treatment has been carried out, so many variable factors develop that there are no definite criteria for evaluation of the results. When it is reported that the sputum is negative for tubercle bacilli, it must be indicated whether it is negative on direct smear, on concentration, on culture or on guinea pig inoculation and, finally, whether the secretions were obtained by bronchoscopic aspiration or by expectoration. Since there is no working classification of pulmonary tuberculosis before treatment is started and since the evaluation of treatment is so indefinite, there will always be a difference of opinion concerning the proper method of treatment for the individual patient.
The treatment of pulmonary tuberculosis can be divided into three major categories: the prophylactic, the medical and the surgical treatments. The prophylactic treatment