Nevil Story Maskelyne

“ Hence I conclude that the substance supposed to be artificially-formed diamond is not diamond and is not carbon, and I feel as confident in the results thus obtained from a few infinitesimal particles that can barely be measured and could only be weighed by an assay balance of the most refined delicacy, as if the experiments had been performed on crystals of appreciable size. ”

“ That it will be solved no scientific mind can doubt, though the conditions necessary may prove to be very difficult to fulfil. It is possible that carbon, like metallic arsenic, passes directly into the condition of vapor from that of a solid, and that the condition for its sublimation in the form of crystals, or its cooling into crystal diamond from the liquid state, is one involving a combination of high temperature and high pressure present in the depths of the earth’s crust, but very difficult to establish in a laboratory experiment. ”

“ The diamond excels all substances in hardness. Its crystals belong to the cubic system, and should not, therefore, present the property of doubly refracting light. Frequently, however, from the influence of strains within the crystal due to inclosed gas bubbles, or other causes, diamonds are not entirely without action on a ray of polarized light sent through them. Finally, the diamond is pure carbon, and, as such, burns entirely away when heated to a sufficiently high temperature in the air, and more vividly so burns, or rather glows away, when heated in oxygen gas. ”