294 



Dr. R. A. Lehfeldt on the 



Characteristic Surface for Phenol-Water Mixtures. 



To complete an account of the behaviour of phenol-water 

 mixtures, it is necessary to draw a diagram of the relations 

 between temperature and concentration ; this is given in 

 fig. 3. Figs. 2 and 3 together, therefore, give a notion of the 

 shape of the " characteristic surface," i. e. the surface showing 

 the relations between concentration, temperature, andpressure. 

 Fig. 2 contains three sections at right angles to the axis of 



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 (jo = l atmo). 



The behaviour of phenol-water mixtures is formally 



