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Mr. W. B. Hardy. 



[Apr. 9, 



Harris.* S is pure salt, W pure water, G pure globulin (edestin). The 

 points on the curves, fixed by actual experiment, are shown in the usual 

 way by dots or crosses. A'B'C is the curve for Na 2 S04, ABC the curve for 

 NaCl. The broken line extending to just beyond B is the probable form 

 of the curve for H 2 S0 4 . The diagram is drawn as an isotherm for NaCl, 

 water, edestin, the areas for the other salts being left out. The context is 

 not very clear on the point, but the temperature of observation seems to 

 have been 20°. 



Each curve clearly consists of two distinct parts, AB, which is . in 

 equilibrium with solid salt, and BC in equilibrium with globulin crystals. 

 The whole surface, therefore, consists of certain areas : — ABC, all points 

 within which represent a homogeneous state, namely, a fluid solution of 

 globulin, salt, and water ; ASB, which is an area of heterogeneous states. 

 Each point in it represents a mixture which cannot exist as a uniform 

 state, but divides into two phases, one a fluid solution on the curve AB, the 

 other a solid which is pure salt. WBGr, again, is an area of mixture which 

 cannot form a uniform state, but which divides into a fluid solution on CB, 

 and into globulin crystals. SBGr, each point within which represents a 

 mixture which divides into a fluid having the composition of B and solid 

 salt and solid globulin. 



In fig. 2, portions of three isotherms for NaCl, water, serum globulin are 



Glob 



