526 



JOHN R. MURLIN 



Hams bottles Ej or E 2 . The air next passes through the 2-way valve, V 2 , 

 and enters a small can, F, which contains dry sodium bicarbonate, where 

 the unweighable and nearly imperceptible sulphuric acid odors are effec- 

 tually removed. The air then returns to the chamber through the by-pass 

 J, or, if it is desired to moisten the air, the current can be deflected by 

 closing the valve, R, in the bypass, J, so as to pass all of the air through 

 distilled water in the Williams bottle K. The air is now free from carbon 

 dioxid and contains the water vapor added in passing through K, but is 

 still deficient in oxygen. This deficiency is made up by admitting oxygen 

 from the pressure cylinder L. The air thus enters the respiration chamber 

 I somewhat moist and with approximately normal percentage of oxygen. 



Fig. 7. Diagram of the respiration apparatus used by Benedict and Talbot in 

 their study of the gaseous metabolism of infants. Description in the text. 



Either series of absorbers may be used as desired, fou if the air current 

 has been passing through the series D x and E A , for a given experimental 

 period, the air can be instantly deflected through the series D 2 and E 2 by 

 turning the valves V x and V 2 . These valves are connected by a long rod so 

 that they may be thrown simultaneously by one movement of the hand. 



Since the air-current is entirely closed a small spirometer S is attached 

 at the upper right hand corner of the respiration chamber, thus providing 

 for an expansion or contraction of the air. A thermometer, T a , in the cover 

 of the chamber and a second thermometer, T 2 , in the outgoing air serve 

 to indicate the temperature changes while the manometer, M, shown be- 

 low the spirometer indicates the pressure of the air in the chamber. 



By noting the increase in weight of the absorbers D x and Ej or D 2 and 

 E 2 the amount of CO\ absorbed is known. It is possible that the amount 



