in which _t_ is the temperature of the calorimeter. The correction for pressure has also been worked out in a series of tables and the logarithmic factor here corresponds to the ratio _p_/760, in which _p_ is the observed barometer. The logarithm of the total volume is recorded as a result of the addition of these three logarithms enumerated, and from this logarithm is expressed the total volume of air in liters. Deducting the sum of the values (_a_) and (_b_) from the total volume leaves the volume of oxygen plus nitrogen. The calculation of the residual volume of nitrogen and the record of the additions thereto was formerly carried out with a refinement that to-day seems wholly unwarranted when other factors influencing this value are taken into consideration. For the majority of experiments the residual volume of nitrogen may be considered as constant in spite of the fact that some nitrogen is regularly admitted with the oxygen. The significance of this assumption is best seen after a consideration of the method of calculating the amount of oxygen admitted to the chamber. RESIDUAL SHEET No. 1. Calculation of residual amounts of nitrogen, oxygen, carbon dioxide and water-vapor remaining in chamber at 8.10 A. M., June 24, 1909. Residual at end of Prelim. period. Exp.: Parturition. No......... Subject: Mrs. Whelan. Calorimeter: Bed. -------------------------------------------+------------------------------- Barometer, 756.95 mm. | Miscellaneous Calculations Temp. cal., 20.08 °C | 875 48.65 -------------------------------------------+ 164.55 25.9 | ------ 90. Apparent Volume of Air | 710.46 ------ | 4.6 164.55 I containing H_{2}O 715. liters | ------ I-II " CO_{2} 781. " | 715.0 I I-III " O+N 755. " | 14 -------------------------------------------+ ------ Log. wt. H_{2}O to residual | 781.0 I-II .0815 = 91116 | 24 Log. I = 85431 | ------ ----- | 755.0 I-III 76547 = 5.88 gms. H_{2}O +----------------------------- Gms. to liters, 09462 | (a) 7.26 l. ----- | (b) 1.57 l. (a) 86909 = 7.25 l. H_{2}O | ----- | 8.82 = l. CO_{2} + H_{2}O | Log. wt. CO_{2} in residual | Log. I-III = 87796 .0438 = 62634 | " temp. = 96912 Log. I-II = 84392 | " pressure = 99856