Len's face was pasty white and for a moment she thought he was going to throw up.

The solution turns yellow in colour, and, when saturated, deposits a pasty mass of crystals.

The heat evolved by this process of solidification retards the fall of temperature; but after this the rate of cooling remains regular until T (750°) on the line Sa (Ar 3) is reached, when a second retardation occurs, due to the heat liberated by the passage within the pasty mass of part of the iron and carbon from a state of mere solution to that of definite combination in the ratio Fe 3 C, forming microscopic particles of cementite, while the remainder of the iron and carbon continue dissolved in each other as austenite.

These materials were heated in pans in the furnace so as to combine in a pasty, half-fused condition.

With 10% of gold present the amalgam is fluid, and with 12.5% pasty, while with 13% it consists of yellowish-white crystals.