ETIOLOGIC STUDIES IN TUBERCULOSIS

The etiology of pulmonary tuberculosis is far from being a closed subject, and this communication is an attempt to supply what seems to some workers missing links in the etiologic chain. The dicta of many authorities have been apparently blindly accepted by their followers. On close scrutiny it is seen that many statements rest on inference rather than on fact. We have attempted in these few experiments on guineapigs to accept no statements, and to trace the tubercle bacillus, if possible, directly from the source of infection to the apparently exposed animal. The final test was of course the necropsy of the guinea-pig. In succession we studied the dust of rooms, the telephone receivers, the eating utensils, the infected hands of patients, the saliva, the transmission by kissing, the infection of tooth brushes, and the danger of flies and of coughing in tuberculous infection for guinea-pigs.

I. THE DUST OF