( 198 ) 



So we have now got two liucs, both starting from point <j in 

 fig. 3. From eacii point below d two more sncli lines may be 

 drawn; but from d itself but one. To find this we must set out 

 from the critical solution of water and phenol. But this is not 

 exactly known. Dr. Scheeinemakehs took a solution, containing- 

 35.77 pCt. phenol wich certainly lies near the critical one. He 

 found : 



Molec. auiliue ou ]00 Mol. 



phenol + aniline. Mixiugteniperature. 



±68° 



20.46 105°5 



23.83 120° 



50.68 135-° 



68.69 144° 



76.88 145° 



80.18 144° 



87.20 ± 137° 



The line that may be deducted from this table is however not 

 given in fig. 3; as far as it is continued, it is entirely above ylm 

 but intersects i/A/; in a point situated between ,^ and the intersection 

 of the two curves g h k and d e. 



Physics. — „Oil. the accurate dcfenninatioii uf the inolecal<ir weiijht 

 of (jnses from their dem^ity." By Prof. J. D. van der Waals. 



From the equation : 



follows 



and 



Z Va m N «2 = po ^0 (1 + «) (1-^) (I + «0 • 



If the quantity N is cfpial for two different gases, it follows 

 from the thesis that at the same temperature Vs »" «^ is the same, 

 that for the two gases iOp i'o(l +a)(l-Z') has also the same value, 

 and therefore also «„(I + a) (1— /<). 



