TECHNIQUE FOR METABOLISM DURING REST. 



107 



train of purifiers consisting of soda-lime bottle and small Williams bottle 

 (see figs. 11 and 12). Thus both samples are taken at identically the 

 same time. 



In figure 8 but one soda-lime and one small Williams bottle are shown. 

 As a matter of fact, looking down on top of the tnble (figure 12) one 

 sees four sets of absorbers. At the bottom of figure 12 is shown the 

 set connected with blower Fi and at the top the set connected with 

 blower F2. As each sampling can and blower is provided with a double 

 set of soda-lime and Williams bottles, we have two series for blower Fi 

 withdrawing air from can Ci and two series connected with blower F2 

 withdrawing air from can C2. With this arrangement we can, by- 

 means of valves Vi and V2 (fig. 12) and their corresponding valves 



Fig. 11. — Top view of lower shelf of absorption apparatus of group respiration chamber. 



The parts are lettered the same as in fig. 8. hi and /12, globe valves for by-passing air-currents from 

 blowers, Fi and F2. wii and mj, rubber tubes for fine regulation of amounts of air delivered by 

 blowers. These tubes are opened and closed by telegraph sounders actuated by contacts 

 di and dj in fig. 13. 



F3 and V4, deflect both air-currents from one series of purifiers to the 

 other at the end of any 20 or 30-minute period and thus begin an- 

 other experimental period without intermission. 



This method of treatment assumes at the start that the same amount 

 of air will be discharged through both 10-mm. openings in the bottoms 

 of cans Ci and C2. Since the discharge from the rotary air-impeller, a, 

 is somewhat nearer to the opening of the bottom of the can Ci than it is 

 to the opening in C2, one might think that there would possibly be more 

 or less of a short-circuiting effect between the discharge of a and the 

 opening B, and inequality in discharge to Ci and C2. This difficulty 

 is avoided by a series of wire screens (W, fig. 9) which breaks up 

 practically all air-currents. Tests have shown that the discharge 

 through the two 10-mm. openings is exactly the same. 



