108 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



To measure the amount of air delivered through these openings is a 

 difficult problem. No anemometer thus far devised can record the 

 discharge of air through these holes with a sufficient degree of accuracy 

 for comparison purposes, but the air discharged must be measured for 

 checking; this problem is intimately connected with the problem of 

 collecting and analyzing a sample of the discharged air, for our funda- 

 mental assumption is that the large proportion of the air will be dis- 

 charged into the room free, but a small sample must be collected for 

 analysis. To assume that there will be constancy in the discharge of 



Fig. 12. — View from above of top of absorption table of group respiration chamber. 



B, circular opening for delivery of air to outside; Ci and d, cylindrical cans on top of wind chest; 

 Li, Ml and L2, M2, duplicate sets of soda-lime and sulphuric-acid containers for absorbing 

 carbon dioxide of air coming from Ci ; L3, M3 and Li, Mi, duplicate sets of soda-lime and sul- 

 phuric-acid containers for absorbing carbon dioxide of air coming from d; Vi and F2, 3- way 

 valves to deflect air from Li, Mi to L2, Mr, V3 and Vi, 3-way valves to deflect air from L3, M| 

 to Li, Mi; P, petroleum manometer for indicating pressure in either Ci or C2; 0, meter for 

 measuring amount of air passed through the system. 



the air through these various holes presumes that the resistance 

 against which the air is discharged should be the same in all cases, that 

 is, there must be atmospheric pressure outside the openings. To dis- 

 charge a definite volume of air against atmospheric pressure and 

 simultaneously collect it presents a new problem. 



COLLECTION OF AIR SAMPLE. 



The collection of the sample of air from the aliquoting device deliv- 

 ered against atmospheric pressure is not unlike an earher experience 

 in the development of the respiration calorimeter at Wesleyan Uni- 

 versity. In this apparatus the Blakeslee pump was made to deliver 

 the air of 49 strokes into the room and of the fiftieth stroke into a pan 

 covered with a rubber diaphragm and delicately counterpoised. From 



