CONSTITUTED OF SPHERICALLY SYMMETRICAL MOLECULES. 



471 



meats on viscosity carried on at Halle, and has compared the results with the 

 formulae of PULUJ and THIESEN. The former agrees remarkably well with the 

 olwervations, the residuals seldom exceeding 3 per cent. THIESEN'S formula agrees 

 even better still, the residuals rarely exceeding 1 per cent. This is not unnatural, as 

 the constants A and B were found by the method of least squares to three or four 

 significant figures. I have taken two of the longest tables given by SCHMITT, and 

 have roughly found the value of k (by trial and error) which makes the formula (34) or 

 (53) agree most closely with the observations. The results are given in the following 



tables* := 



VISCOSITY of Mixtures of Argon and Helium at I'B" C. 



VISCOSITY of Mixtures of Oxygen and Hydrogen at 15 C. 



* Iii the first table the experimental constants used were as follows: /*x 10~ 7 = 2220, /*' x 10 T = 1966, 

 w = 1-224, w' = 0-125 (relative to oxygen), po (at 15 C.) = 0-001353, DU (at 15 C. and in C.G.S. 

 units) =0-705 (from SCHMIDT'S experiments, rf. p. 478). The values of E, F, G, F! were 7-B97, 6-897, 

 1 -069, and 2 -776 x 10 4 respectively. 



In the second tabje the values of /*x 10 7 were 2014 and 878, w = 1, */ = 0-0629, p<> = 0-001353, 

 D, 8 (from JACKMANN'S experiments, cf. p. 478) = 0-760, at 15 C. and in C.G.S. unite. The values of 

 E, F, G, FI were 11-34, 9-676, 1-049, and 5'205x 10 4 respectively. 



