sH 



Fig. 15.— Bohr meter, a, water bath; b, leveling board; c, moistener. 

 (For description, see page 47.) 



Fig. 16.— General view of the spirometer unit. 



A, rotary blower; B, trap; C and D, Williams bottles containing sulphuric acid for absorbing 

 water-vapor; E, soda-lime container for absorbing carbon dioxide; F, Williams bottle containing 

 sulphuric acid; G, sodium-bicarbonate can; H, air-pipe leading from G to three-way valve, X; 

 J, handle for turning three-way valve; L, large tube leading from three-way valve to spirometer 

 M; N, weight counterbalancing movable arm, LHWW; 0, clutch for holding movable arm in 

 place; KP, handle and rod for turning two three-way valves at either end of carbon-dioxide 

 absorption system; Q, large oxygen cylinder; R, Erlenmeyer flask partly filled with barium- 

 hydroxide solution; S, three-way valve; T, ventilation adder wheel; U, Bohr meter immersed 

 in water; V, typical graphic record; X, three-way valve; Y, pneumatic nosepieces; WW, connec- 

 tions for changing angle of three-way valve. 





