44 



Composition of the Atmosphere 



England. His results, which were first published in a condensed form, 1 

 were subsequently given more in detail as a part of a larger publication. 2 

 Using for the most part the explosion apparatus of Bunsen, although 

 making several ineffective attempts to secure accurate results by means 

 of Liebig's pyrogallic-acid method, Smith made an enormous number of 

 analyses of outdoor air in connection with his investigation of the ven- 

 tilation of houses. In his book, which contains the best collection of the 

 literature and analyses of outdoor air thus far published in English, he 

 reports over 100 determinations of the oxygen content of outdoor air. 

 Firmly impressed with the belief that the presence of putrefying organic 

 matter requires a material draft upon the oxygen of the air, Smith made 

 a comparative study of the air collected at the front door of the labora- 

 tory and in outhouses in the near neighborhood. His results are given in 

 table 25. 



Table 25. Determinations made by Smith of oxygen in outdoor air and in the 



air of outhouses in Manchester. 



A very extensive examination of the air of London was carried out by 

 Smith in November 1869. These analyses give us a method of judging of 

 the accuracy of Smith's method and the agreement of duplicates. They 

 are in part reported in tabic 26. 



The probable influence of weather conditions, especially moisture 

 and fog, led Smith to investigate the changes in oxygen content as affected 

 by this factor. Five analyses are reported of air taken near the labora- 

 tory in Manchester during wet weather, the results being 20.90, 21.01, 

 21.01, 21.05, and 20.96 per cent of oxygen, respectively, with an average 



1 Smith, Memoirs of the Literary and Philosophical Society ofjManchester, 1864-65, 

 ser. 3, 3, p. 5. 



2 Smith, Air and rain; the beginnings of a chemical climatology. London, 1872. 



