The analogy between the breaking up of a solid solution on cooling and the formation of a eutectic is obvious.
The mixture C has a lower freezing or melting point than that of any other mixture; it is called the eutectic mixture.
It is evident that every mixture except the eutectic mixture C will have two halts in its cooling, and that its solidification will take place in two stages.
The two sloping lines cutting at the eutectic point are the freezing-point curves of alloys that, when they begin to solidify, deposit crystals of lead and tin respectively.
Osmond, shows the structure of a silver-copper alloy containing considerably Eutectic more silver than the eutectic.