8 



NEW HAMPSHIRE EXPERIMENT STATION [Bull. 261 



the alkali, usually soda-lime. The mass of soda-lime, the mass of the 

 container, and particularly the poor heat-conducting qualities of the glass 

 bottle originally used in the oxy-calorimeter resulted in a very sluggish 

 temperature adjustment after the combustion ceased. The return of the 

 air temperature to its initial point was in part aided, especiall}'' under 

 the temperature conditions prevailing in the laboratory during the win- 

 ter-time, by passing air from the combustion chamber through a metallic 

 U-tube dipped in ice water. When summer temperatures prevailed, this 

 cooling device was found inadequate and direct cooling of the soda-lime 

 container became necessary. With imperfect temperature adjustment the 



Fig. 1. The spirometer type o/ oxy-calorimeter. 



A, combustion chamber; c, tube conducting air from base of com- 

 bustion chamber to metal soda-lime can, B; L, lug for suspension of 

 soda-lime container over a reservoir of cold water; m, rubber band to 

 hold cover of can, B, securely in place; C, blower; S, spirometer; K, 

 petcock for introduction of oxygen; f, tube leading into combustion 

 chamber. 



