Abstract
In any study of water loss from the human body it is necessary to measure that which leaves the respiratory system. Methods have been described, but they are either inaccurate or cumbersome. It is beyond the scope of this paper to review the methods used in the past to measure the water loss through the pulmonary system; many of these are referred to in several excellent discussions on insensible perspiration.1Galeotti and his associates2and Weyrich3used bottles of sulfuric acid or calcium chloride to trap the expired water and measure gravimetrically the water collected. These are not simple procedures, and their accuracy is not well established. The observers did not control the conditions of the air inspired. The paper by Galeotti and Signorelli2aincluded a review of some of the early methods used to measure expired water. Loewy and Gerhartz4measured the temperature of