118 



Mr. W. F. Barrett on a Physical 



It will be seen in the above Table that the absorption suddenly 

 rises at five-tenths of an inch : it will also be observed that the 

 effect of filling the tube with 7 inches of dry air adds scarcely 

 anything to the previous absorption. 



These results, with a few others not before recorded, are placed 

 together in the following Table, in which the first column shows 

 the absorption by carbonic acid alone, and the second the absorp- 

 tion by the same amounts of carbonic acid added to about 20 

 inches of dry air, the absorption by the latter being nil : — 









Table XII. 





Tension, in C 



Absorption per 100 by 



"arbonic acid 



Dry air and 



inches. gas alone. 



carbonic acid 



0-5 .... ... 



32-1 



10 









45 



48-4 



1-0 









.' 44-8 



48-2 



1-1 











49-4 



1-2 









... 



510 



1-2 











50-7 



1-2 









... 



504 



1-3 









47-7 



520 



1-4 









... 



529 



1-4 . 









... 



51-8 



1-5 









50-8 



53-4 



1-5 









... 



535 



1-7 









51-2 



54-5 



20 









53-1 



573 



2-0 









53-0 



56-8 



2-0 









53-0 



56-1 



2-5 









549 



... 



2-5 









54-1 



. .. 



The slight discrepancy between some of the repeated observa- 

 tions is probably the result of a small chemical difference in the 

 carbonic acid prepared at different periods. 



This Table gives us the power of calculating the percentage of 

 carbonic acid in the different samples of breath ; to obtain greater 

 accuracy, omissions in Table XII., and the intervals between the 

 tenths of an inch, are calculated and given with the mean expe- 

 rimental results in the annexed Table. 



