^-^0 Prof. J. r. Kueiien on the 



selected the set which had beeu carried out with the mixtures 

 in whose purity we had the greatest confidence. 



Table I. — Ethane and Methyl-alcohol. 

 Critical points. 



Temp. 



Press. 



Temp. 



78-4 



Press. 



Temp. 



Press. 1 



241-2 



80-0 



1350 1 



18-6 



114-7 ! 



241-1 



80-45 



74-6 



133-0 ; 



13-2 



118-0 



2400 



81-5 



70-8 



131-5 



12-4 



118-5 



219-0 



100-0 



66-4 



129-5 ! 



— -6 



144 



216-1 



101-5 



62-3 



127-0 



In 



150 



160-8 



136-5 



570 



124-5 : 



2-5 



155 



156-5 



138-0 



51-9 



121-5 1 



2-6 



152 . 



154-2 



138-7 



45-8 



118-5 1 



3-6 



156-5 1 



151-5 



139-7 



41-7 



116-5 1 



44 



161-5 1 



131-9 



143-5 



36-0 



114-5 i 



5-3 



168 ; 



128-5 



144-0 



33-8 



114-7 1 



6-3 



175 



126-0 



144-5 



26-4 



1130 







i Ethane 



Vapour aud upper 1 

 liquid J 



1 



1 Temp. 



Press. 



i 32-16 



48-9 



i 35-37 



520 



Fig. 1 shows the critical curve as plotted from Table I. 

 Starting from C2, the critical point of methyl-alcohol, the curve 

 runs at first in a perfectly normal manner ; it ascends, passes 

 through a maximum near 120° C, and then falls as if tending 

 towards the critical point of ethane, Ci ; but, instead of com- 

 pleting its course in that manner, the curve passes through a 

 minimum pressure between 25° and 30°, and then begins to 

 rise rapidly ; as far as the experiments could be carried, i. e. 

 up to 275 atmospheres, the curve continues on its course 

 upwards without further change. It is interesting to coui- 

 pare the completed diagram with the corresponding diagram 

 for the higher alcohols '^. 



Further light is thrown on the complicated phenomena 

 which these mixtures display by a consideration of the 

 saturation-curves in the volume-composition (y—x) din gram 

 (temperature constant) and the plaits on the van der Waals"* 

 -^^r surface, of which these saturation-curves form the projec- 

 tion "j". Let us follow the development of these curves as the 

 temperature is gradually lowered. The saturation-curve 



* Kuenen & Robson, I. c. p. 199, fig. 8. 

 t lid. I. c. pp. 194-197, figs. 6, 7. 



