Traditionally, in trials for treatment of TB, a new drug is administered in combination with two or more other antituberculous agents of known effectiveness over a long period of time. In this setting, it is difficult to determine the effect of any single drug or dose level. Development of new agents for the treatment of TB may be accelerated by a methodology in which a new agent could be evaluated for activity by administering it as a single agent over a short time period. This study utilizes a method to measure the amount of bacteria present each day in the lungs.