Change of Phase under Pressure. I. The Phase Diagram of Eleven Substances with Especial Reference to The Melting Curve
The detailed presentation of data follows. Besides giving the data actually found in this present investigation (which in most cases are shown with sufhcient accuracy by the points on the diagrams), the attempt has been made to collect all previous data bearing on the point, and to give some discussion of the most probable values. This would not be necessary if it were the only object of this paper to find the most probable course of the melting curve. In addition to numerical data, any details
... l data, any details of manipulation or of computation peculiar to the individual substances are given; in particular the extent of the region through which search was made for other solid forms. Pctessiznn. -The potassium was obtained from Eimer and Amend. The 6rst sample used was very carefully puri6ed by the following method. The commercial lumps were placed under gasolene in a glass receiver, the gasolene removed with an air pump, and the potassium melted and run into a connecting vessel. This connecting vessel was constructed so as to form part of a still, from which the potassium was distilled at high vacuum into a third vessel. The third vessel was then sealed o6 from the still and placed in the thermostat, where about tw'o thirds of the potassium: was allow'ed-to crystallize slowly. The liquid metal was then drained oN and the pure crystals used for the first run. But subsequent work show'ed all these precautions to be unnecessary; the commercial metal is pure enough if the scum of oxide is removed by the first of the processes described above.~C ontinued from page x4x. &53'