( 185 ) 

 p— iO . . . . hv = 0,0010 

 p = 30 A. = 0,0014 



p = 50 Ay = 0,0026 



Also from Mr. Kuenen's values, about which he himself remarks, 

 that they show but little regularity, we get the impresyion, that 

 the exact determination touches the limit of the errors of observation. 



From the observation at 433° we find if .« = V4 



p = 10 A„ = 0,00095 



p = 50 A« = 0,00118 



pz=50 A„=: 0,00152 



According to thci formula (-1) A» must be smaller at a higher 

 temperature, which is also confirmed by the calculated values; for 

 the rest the increase is not so quick at 433° as at 403°. But I 

 repeat, what I said before, that though the approximative formula 

 gives a constant value for Ay, we want more accurate formulae, to 

 indicate the real course. 



Let us compare, in order to judge about the degree of approxi- 

 mation, with which the thesis of Mr. Amagat holds true, the cal- 

 culated quantity A« with the value of A;,. By A^ we represent the 

 difference between the pressure of a mixture and that pressure, 

 which we should find if the law of Dalton held good. 



If we take in a volume v first I — x molecules of the first sub- 

 stance and if we call p^ the pressure, after that x molecules of the 

 second substance, with the pressure p^ ; and finally a mixture with 

 pressure p, then Aj> = p — {Pi -{-p.;,). 



V 



In the first case the molecular volume is ; in the second case 



1 — £ 

 V 



— , and for the mixture i'. So we have the three following equations : 

 x 



13* 



