87 



VISCOSITY OF GASES 



227 



The new formula therefore agrees with the observations 

 not essentially worse than Schumann's, which contains 

 a disposable constant. For the esters investigated by 

 Schumann I have likewise calculated the following values, 

 which I tabulate opposite the observed values : 



Values of 10 6 rj. 



The calculated numbers fit in well as a rule with the 

 course of those observed. We may therefore assert with 

 certainty that Sutherland's theory corresponds pretty 

 exactly to reality even in the limiting case now considered, 

 in which the cohesive forces of the vapour are taken ex- 

 tremely large. The deviations of the theoretical formula 

 from the results of observation are always only a few 

 hundredths of the magnitudes measured. We might there- 

 fore defend the view that the differences may be due only to 

 errors of observation, arising partly in the measurement of 



Q 2 



