DR. R. ANGUS SMITH ON THE 



Bunsen^s analyses of air at Heidelberg are as follows : — 



Oxygen. 





Oxygen. 



20-970 





ao-927 p. c. 



2o"963 





20-919 



20*927 





20-880 



20'9i4 





20-921 



20*950 





20-892 



20-906 





20-840 



20-943 





20*859 



• 20-927 





20-925 



20-934 





20-940 



20-928 





20-937 



20*911 





20-952 



20-889 





20-953 



20-928 





20-964 



20-927 





20-960 



Average 



20-924 ... 



... Lowest 20*840 



E. F. Marchanil finds 



20*9 to 21'0 



Mean 





20-Q7 



Graham gives 20-9 



Liebig gives 20-9 



Regnault has made the greatest number of analyses ; no 

 man can doubt his power of analyzing well^ and he is famous^ 

 above all things^ for his laborious accuracy. Probably 

 his analyses represent most nearly the true composition 

 of the atmosphere. The analyses made by Bunsen deserve 

 equal respect : he is also a man famous for the minute 

 accuracy of his details, and I would not for a moment 

 put him second to Regnault or to any man ; both stand 

 before us as the best specimens of chemical investigators — 

 both living, and in their prime. This is a strong argument 

 for preferring their work to the work of chemists of a past 

 generation. These two have greatly improved the methods 

 of analysis. Still I prefer to take Regnault's results, be- 

 cause they are obtained by a more extensive inquiry. Per- 

 haps the court of the laboratory where Bunsen obtained 

 his specimens may have contained less oxygen than the 

 purest air ; at any rate, we cannot doubt Bunsen^s accuracy, 

 especially when he gives us these as model analyses. 



