The use of the spirometer as a clinical instrument of precision, introduced by Jonathan Hutchinson in 1846, has been brought into more general use through the more recent researches of Peabody,1 Wentworth,2 Dreyer,3 West,4 Wilson, Edwards,5 Lundsgaard, Van Slyke,6 Hewlett and Jackson7 and others. The normal standards suggested by Hutchinson have been modified, and the relation to the body measurements of height, weight, body surface, chest volume and circumference have been determined for various groups of persons. The value of spirometry as an index to the patient's clinical condition has already been demonstrated in cardiac8 and pulmonary disease.9 Conditions necessary for the more general adoption of this method are: ( 1) a simple technic; (2) accurate normal standards with knowledge of the normal range, and (3) knowledge of the factors influencing vital capacity. The first is fairly standardized, and although the apparatus is cumbersome and not easily portable, it is