21i) 



1. The gas becomes heated during the combustion, so care must be 

 talien to determine the final temperature at which the gas is measured. 

 Corrections must be made for all temijerature changes. 



2. A correction must be made for the carbon dioxide which remains 

 in the quartz tube after the combustion. This disadvantage can be over- 

 come perhaps by the use of a smaller bore capillary quartz tube in which 

 the volume is so small that a correction is unnecessary. 



IndiaiKi T'>ii}-(rsit!/, Blooitiinf/ton. 



