Summaryo(1)While “gassing” appears to bear a relatively unimportant part as regards the after incidence of tubercle, in gunshot wound injuries of the chest (all types, surface and penetrating), the incidence of pulmonary tuberculosis forms a small but appreciable percentage of not less than 0.5. This percentage, however, is more than double that occurring amongst the average civil population according to municipal and health statistics, and greatly in excess of such returns as are available in relation to the Services; the latter returns, however, are more comparable since the Services deal with a similar type. This percentage is likely to become considerably higher when final results can be formulated, for the number of men disabled from chest trauma is a limited and decreasing one, whilst further similar cases of pulmonary tuberculosis in these men are likely to emerge. If the relative incidence of pulmonary tuberculosis could be applied to men suffering only from penetrating chest injuries, this percentage 0.5 would in all probability be considerably exceeded.(2)Surface injuries not involving the thoracic cage and contents appear to be of relatively small importance in connection with the after occurrence of pulmonary tuberculosis.(3)When the pulmonary tissue has been definitely injured, and especially when a foreign body is retained in or near the damaged area, activation of tubercle may occur in the organ affected, even at an indefinite period later, and it is logical to assume that there may be a direct relationship. This possible development, therefore, requires consideration when prognosis is under review. While “gassing” appears to bear a relatively unimportant part as regards the after incidence of tubercle, in gunshot wound injuries of the chest (all types, surface and penetrating), the incidence of pulmonary tuberculosis forms a small but appreciable percentage of not less than 0.5. This percentage, however, is more than double that occurring amongst the average civil population according to municipal and health statistics, and greatly in excess of such returns as are available in relation to the Services; the latter returns, however, are more comparable since the Services deal with a similar type. This percentage is likely to become considerably higher when final results can be formulated, for the number of men disabled from chest trauma is a limited and decreasing one, whilst further similar cases of pulmonary tuberculosis in these men are likely to emerge. If the relative incidence of pulmonary tuberculosis could be applied to men suffering only from penetrating chest injuries, this percentage 0.5 would in all probability be considerably exceeded. Surface injuries not involving the thoracic cage and contents appear to be of relatively small importance in connection with the after occurrence of pulmonary tuberculosis. When the pulmonary tissue has been definitely injured, and especially when a foreign body is retained in or near the damaged area, activation of tubercle may occur in the organ affected, even at an indefinite period later, and it is logical to assume that there may be a direct relationship. This possible development, therefore, requires consideration when prognosis is under review. In conclusion I have to acknowledge my indebtedness to the Director-General of Medical Services, Sir Lisle Webb, for kindly permitting me to use the material and information forming the basis of this paper.