430 The Viscosity of Mixed Gases. 



2 and N 2 . 



r r/ 2 . m v m v ,0,. a C r ,O a . 



10 -875 32 28 127 109 117 



njn 2 1 1/2 1/3 1/9 



r, exper 935 '914 905 885 



v calcul -937 '916 -905 -887 



2 and CO. 



t] v t] 2 . m v m v &. 2 C 2 . i°a- 



10 -870 32 28 127 100 113 



njn 2 3 2 11/2 1/3 



,; exper '967 "959 -936 -913 '904 



i? calcul -967 -957 '933 '912 '900 



The only pairs of gases for which Graham's data have not 

 been given are N 2 and H 2 and NO and H 2 , but the physical 

 constants for N 2 are almost identical with those for C0 2 , and 

 the viscosities of its mixtures are almost the same as those of 

 mixtures of C0 2 ; for NO some of the data necessary for the 

 calculation are lacking. 



Pulnj measured the viscosities of a large number of mixtures 

 of C0 2 and H 2 by the method of the vibrating disk (Sitzb. 

 Akad. Wien, lxxix.), giving the absolute values at 14°*7 C; 

 thus rj x is '000147 and rj 2 is '000089 ; the other constants 

 required in the calculation remain as above, and we have the 

 following comparison of experiment and calculation values 

 of Wrj :— 



njn 2 .... 9 4 2*6 -77 -36 -19 -11 068 04 '025 017 

 Exper.... 148 149 150 148 140 131 122 111 103 99 98 

 Oalcul.... 147 147 147 142 133 122 113 106 100 96 94 



The agreement between the formula (11) and experiment 

 is not so good here as in Graham's mixtures of C0 2 and H 2 , 

 which means that there are discrepancies between Graham's 

 and Puluj's measurements ; these are probably due to slight 

 impurity to which the viscosity of hydrogen is sensitive. But 

 even if the agreement is not good in the details of the last 

 comparison, the main phenomenon of the experiments is 

 closely paralleled by the formula, for in the results both of 

 experiment and formula the addition of one volume of hydro- 

 gen to 2*6 volumes of carbonic dioxide hardly affects the 

 viscosity of the carbonic dioxide. 



The case of CH 4 and H 2 in the previous comparison is the 

 most interesting, as both experiment and the formula make 

 the viscosity of a mixture of equal volumes of the two gases 

 greater than that of pure CH 4 . It must be remembered that 



, 



