History of Air-Analysis 



41 



World as in the Old World, but not absolutely constant. The increase 

 in the percentage of carbon dioxide, which rose as high as 0.49 per cent 

 14 or 16 times the normal percentage is attributed by Lewy to the in- 

 fluence of large forest fires and the presence of volcanoes. 



Table 22. Analyses of air from New Granada. 



Date. 



1848. 



Jan. 25 

 Feb. 7 

 Feb. 18 

 Mar. 3 

 Mar. 29 

 Aug. 5 

 Aug. 

 Apr. 

 Aug. 

 July 

 July 



Place. 



Elevation. 



Average of 3 analyses 

 of each sample. 



Carbon 

 dioxide. 



Oxygen. 



Santa Marta . . . 



Mompox 



Magdalena River 



...Do 



Honda 



Ambalema 



Esperanza 



Guaduas 



Santa Ana 



Bogota 



Montserrat .... 



meters. 







38 



242 

 282 

 396 

 996 

 998 

 2645 

 3193 



p. ct. 



0.046 

 .031 

 .033 

 .046 

 .032 

 .112 

 .245 

 .031 

 .123 

 .050 

 .052 



p. ct. 



21.02 



21.05 



21.03 



21.00 



20.99 



20.55 



20.33 



21.00 



20.54 



21.03 



20.99 



Table 23. Analyses of air from Bogota (2645 meters). 



The hydrogen-explosion method and the weighing of the amount of 

 oxygen absorbed by a metal or by phosphorus involved an exceedingly 

 elaborate technique and restricted the number of observations that could 

 possibly be made by one man in a day. In 1851 there appeared the de- 

 scription of a method of absorbing oxygen by means of an alkaline solu- 

 tion of pyrogallic acid. Liebig 1 reported the results of 11 analyses, with 

 percentage values as follows: 20.99, 20.89, 21.03, 20.95, 20.77, 20.92, 

 20.90, 20.80, 20.75, 20.76, 20.93. With this method he maintained that 

 in an hour half a dozen analyses could be carried out. Gallic acid could 

 also be used instead of pyrogallic acid, although, according to Liebig, the 

 absorption required a longer time than with pyrogallic acid, i.e., lh to 2 

 hours instead of as many minutes. Liebig gives the results of 8 analyses 



1 Liebig, Annalen der Chemie und Pharmacie, 1851, 77-78, p. 107. 



