How and When Diamonds were Made by Nature. R.B. CROCKER. (Chem. News, civ, 248.)--Facts are given from which the theory is deduced that diamonds were formed before organic matter, when the earth's atmosphere consisted mostly of CO and CO2, and the metallic elements were in the molten state. Molten iron, solidifying in fissures and cavities filled with CO and CO 2, imprisoned them, and, under the enormous pressure due to cooling and contracting the oxygen united with the iron and the carbon crystallized as diamond.