Abstract
The procedure of preparing single crystals of nickel and copper by the method of slow solidification, and the apparatus for producing and observing light figures of crystals were described. Single crystals of nickel and copper were etched with aqueous solutions of acids and salts, of various concentrations, for different time-intervals, and light figures on the three principal crystal planes (100), (110), and (111) were observed and examined in detail in view of utilizing them for determining the orientations of the said metal crystals. The symmetry characteristics of the light figures are naturally invariable, while their forms may, in general, vary with an etching reagent, its temperature, and the time of etching. The most suitable light figures for the determination of the crystal orientation were found to be those on (100) planes, except a few cases for nickel crystals.
