THE MINERALOGRAPHY OF THE FELDSPARS 283. 
senting the freezing temperatures (and called the liquidus) falls 
off or is depressed as amounts of the second component are added, 
JUN LVEAdWIL 
Fic. rs.—Diagram illustrating the construction of the thermo-equilibrium diagram of a eutectiferous system 
until (near the center of the present diagram) a point is reached 
where the sum of the two components freezes at a temperature 
lower than in any other proportion. This is the ‘“‘eutectic point” 
