History of Air-Analysis 



61 



water; 11 analyses made on the same sample of air gave percentages of 

 oxygen varying from 20.91 to 21.19, with an average of 21.08, and on 

 another day 6 analyses of the same sample of air gave percentages varying 

 from 20.96 to 21.03, and averaging 20.99. The author also reports two 

 analyses of air by pyrogallic acid, showing 20.93 and 20.88 per cent of 

 oxygen, respectively. 



Employing a reaction first utilized by Winkler 1 to determine the oxy- 

 gen dissolved in water, Chlopin 2 utilized the interaction between man- 

 ganous salt and oxygen in the presence of potassium iodide to determine 

 the oxygen content of gaseous mixtures by titration. The results of a 

 series of analyses of the air taken in the court of the Hygienic Institute in 

 Dorpat are given in table 44. 



Table 44. Results of analyses of outdoor air, made by Chlopin. 



A second paper by Chlopin 3 reports analyses of outdoor and room 

 air, but does not indicate which are those for outdoor air. 



Samojloff and Iudin, 4 describing a method of gas-anafysis in which a 

 modified Bunsen apparatus was used, have published a considerable num- 

 ber of analyses of outdoor air. Using explosion with hydrogen to de- 

 termine the oxygen, they found 20.97, 20.97, 20.96, 21.00, 20.99, 20.99, 

 21.01, 20.99, 20.96, 20.92, 20.97, and 20.98 per cent. Two analyses with 

 pyrogallic acid gave 20.91 and 21 per cent of oxygen, respectively. 



In 1902, Krogh, of Copenhagen, on a voyage to the island of Disko, 

 west of Greenland, latitude 70 north, undertook a number of analyses of 

 atmospheric air. While the prime object of his research was to study the 

 carbon-dioxide tension in natural waters and especially in the sea, these 

 determinations were combined with direct analyses of the atmospheric 

 carbon dioxide and oxygen. The analyses were made with a Haldane 

 apparatus, the burette of which contained only 10 c. c. The accuracy 

 is given as 0.005 to 0.01 per cent and the numerous double determinations 

 generally agree within these limits. 5 The extensive series of oxygen de- 



1 Winkler, Berichte der deutschen chemischen Gesellschaft, 1887, 21, p. 2843. Also 

 ibid., 1889, 22, p. 1764. 



2 Chlopin, Archiv fur Hygiene, 1899, 34, p. 71. 



3 Chlopin, Archiv fur Hygiene, 1900, 37, p. 329. 



4 Samojloff and Iudin, Le Physiologiste Russe, 1901, 2, p. 171. 



5 Krogh, Meddelelserom Greenland, 1904, 26, p.333. 



