46 



CALORIMETERS FOR STUDYING RESPIRATORY EXCHANGE, ETC. 



chamber, the outer wall in front of the glass windows is made of glass 

 rather than asbestos. The front section of the outer casing can be removed 

 easily for the introduction of a patient. 



In this chamber it is impossible to weigh the bed and clothing, and hence 

 this calorimeter can not be used for the accurate determination of the 

 moisture vaporized from the lungs and skin of the subject, since here (as 

 in almost every form of respiration chamber) it is absolutely impossible to 

 distinguish between the amount of water vaporized from bed-clothing and 

 that vaporized from the lungs and skin of the subject. With the chair 

 calorimeter, the weighing arrangements make it possible to weigh the chair, 



1 Meter 



Fio. 26. Cross-section of bed calorimeter, showing part of steel construction, also copper and zinc walls, 

 food-aperture, and wall and air-resistance thermometers. Cross-section of opening, cross-section of 

 panels of insulating asbestos, and supports of calorimeter itself are also indicated. 



clothing, etc., and thus apportion the total water vaporized between losses 

 from the chair, furniture, and body of the man. In view of the fact that 

 the water vaporized from the skin and lungs could not be determined, the 

 whole interior of the chamber of the bed calorimeter has been coated with 

 a white enamel paint, which gives it a bright appearance and makes it much 

 more attractive to new patients. An incandescent light placed above the 

 head at the front illuminates the chamber very well, and as a matter of 

 fact the food-aperture is so placed that one can lie on the cot and actually 

 look outdoors through one of the laboratory windows. 



Special precaution was taken with this calorimeter to make it as com- 

 fortable and as attractive as possible to new and possibly apprehensive 

 patients. The painting of the walls unquestionably results in a condensa- 

 tion of more or less moisture, for the paint certainly absorbs more moisture 



