37S 



VAPOR-DENSITIES. 



due to the neutral gas. This result, which may be extended to any 

 number of neutral gases, is simply an expression of Dalton's Law. 



We now proceed to the comparison of the formulae, especially of 

 equation (6), with the results of experiment. 



TABLE I. PEROXIDE OF NITROGEN. 

 Experiments at Atmospheric Pressure. 



MlTSCHERLICH, R. MtJLLER, DEVILLE and TROOST. 



Peroxide of nitrogen. If we take the constants of the equation for 

 this substance from the paper already cited,* we have 



15-89(D- 1-589) 3118-6 

 log (3-178-DV* ; 27q +logff-12-451, (10) 



\O JL I O ^^ U 'I l/Q ~j~ & i O 



t c denoting the temperature on the centigrade scale. The numbers 

 3-178 and 1*589 represent the theoretical densities of N 2 O 4 and NO 2 



*8ae equation (336) on page 177, also the following equations in which the density 

 b given in terms of the temperature and pressure. In comparing these equations, it 

 must be observed that in (336) the pressures are measured in atmospheres, but in this 

 paper in millimeters of mercury. 



