the Mutual Solubility of Liquids. 201 



Table XI.— Ethane and less Butyl Alcohol (II.). 



t. 



I 





153 

 22-95 



31-95 



381 

 38-55 

 38-75 

 398 



3875 



39-75 



3995 



50-0 



600 



3348 



39-36 



! 4707 



C. 



53 67 



53-97 



C. 55-04 



5422 

 55-81 

 56-19 

 7004 

 81-78 



1 Vapour disappears by compression; 

 two phases. 



1 Three phases. 



"1 Compression of the liquids gives 

 critical phenomena and mixing ; 



\ at 38°"75 near the top and at 

 higher temperatures nearer and 



) nearer to the bottom of the tube. 



With isopropyl alcohol we did not obtain such good results 

 as with the other alcohols, probably owing to its impurity. It 

 gives three phases, between two limits of temperature, just as 

 the other alcohols do, the upper critical temperature being 

 about 44° C. The lower critical point could not be determined 

 with any accuracy as critical phenomena of the liquids in the 

 presence of vapour were observed between wide limits of 

 temperature (38° to 42°) instead of at one temperature only. 

 Also at temperatures below 38° (down to about 25°) three 

 layers were still formed, and retrograde condensation was 

 observed — all this pointing to the presence of a third substance. 

 Though the butyl alcohol also was not very pure (as shown 

 by the boiling-point), its impurity appeared to have a much 

 smaller effect on the phenomena than in the case of isopropyl 

 alcohol. 



With the mixture of isoamyl alcohol and ethane, the last 

 one we tried, no three phases were observed, although three 

 decreasing proportions of alcohol were used. The plait-point, 

 however, still retains the same character as with the other 

 alcohols, that is, it is turned considerably towards the a?-axis, 

 as will be seen from Table XIV. This particular mixture 

 displayed plait-point phenomena at 45° C. ; up to 107 o, 6 C, 

 the highest temperature we could apply with safety on account 

 of the high pressures, it still showed (retrograde) condensation. 

 With this mixture therefore the plait-point temperature and 

 the critical temperature, which with such mixtures as carbon 

 dioxide and methyl chloride, carbon dioxide and air, &c. 

 are almost identical, differ considerably. The same thing 



