This study of emphysema and asthma was undertaken with the idea that great changes in the dead space must occur when an emphysematous patient suffered an asthmatic attack.
It was suggested in a former publication on emphysema1 that the dead space was probably much enlarged in emphysema. If this were true then the dead space of an emphysematous patient must undergo a great change during an attack of asthma. We have succeeded in getting two emphysematous patients who had frequent attacks of asthma. After some persuasion, these patients learned to breathe through the Zuntz apparatus during asthmatic attacks. The asthma of both patients could always be relieved by subcutaneous injections of epinephrin. In this way we had numerous opportunities to compare the minute volume of air and the alveolar air of the emphysematous state with the asthmatic state. Much to our surprise we found the