From The Elements of the Science of Nutrition by Graham Lusk, published by W.B. Saunders, 1917, page 68-69.
From “Experiments on the metabolism of matter and energy in the human body, 1900-1902”. US Department of Agriculture, Office of Experiment Stations – Bulletin No. 136, by W.O. Atwater and F.G. Benedict, frontispiece.
The respiration chamber was an open-circuit design. Carefully conditioned room air was drawn into the chamber and then evacuated through soda-lime canisters. The chamber was carefully insulated and kept at a constant temperature by circulating water.