NEW FORMATION OF DIAMOND
shallow watch-glass and the selection made under the microscope. The residue, after thorough washing and then heating in fuming sulphuric acid, was washed, and the largest crystalline particles picked out and mounted.
From the treatment the residual crystals had undergone, chemists will agree with me that diamonds only could stand such an ordeal; on submitting them to skilled crystallographic authorities my opinion is confirmed. Speaking of the largest crystal, one eminent authority calls it " a diamond showing octahedral planes with dark boundaries due to high refracting index." After careful examination, another authority writes of the same crystal diamond, " I think one may safely say that the position and angles of its faces, and of its cleavages, the absence of birefringence, and the high refractive index are all compatible with the properties of the diamond crystallising in the form of an octahedron. Others of the 125
