CARBON DIOXIDE AT DIFFERENT TEMPERATURES. 



235 



than in the case of air, so a preliminary value of the temperature coefficient was 

 obtained which served for the purpose of calculating the corrections. 



The complete tables of the observations are preserved in the archives, but the 

 following abridged tables show the main quantities upon which the values of the 

 specific heat depend. The tables correspond to those given on pp. 226-228 for air ; 

 two additional columns are added, one to denote the number of the experiment and 

 one to denote the number of the bottle used in that experiment, and also whether it 

 was full (F) or half empty (E) at the commencement of the run. 



Instead of alternating the quick and slow flows, two or three runs with large flows 

 were generally performed first, and followed by two or three runs with small flows, in 

 order to economise gas. In such cases, if one of the large and one of the small flows 

 were performed with fresh bottles, while another pair were performed with half empty 

 bottles, two values of the specific heat were calculated, one from the pair with fresh 

 bottles and one from the pair with half empty bottles. In this way each value ot 

 the specific heat was calculated from two runs in which the composition of the gas 

 was practically the same. This is an advantage, for although the presence of a little 

 air in the C0 2 only affects the measured value of the specific heat to a very small 

 extent, the error becomes magnified if the composition of the gas differs in the 

 two flows. 



(28) ABRIDGED Tables for the Main Calorimetric Experiments on Carbon Dioxide. 



Table I. Air Temperature. 



Mean values for the specific heat at 20 C. = 0-20180 cal. per gr. degree. 



2 H 2 



