Leisure hours among the gems

by Augustus C. Hamlin

The diamond is now recognized by the chemist as a crystalline form of pure carbon. Newton, in 1675, with the wonderful penetration of his genius, and reasoning from the high refractive power of the gem, which so far exceeded the degree due its density, believed it to be combustible. More than a century later the experimentalists of the Academy of Florence strengthened this view by destroying it in the focus of powerful burning mirrors. Lavoisier, however, dispelled all doubts concerning its combustibility by burning it under a receiver filled with oxygen gas. It has since been ascertained that a temperature of 14° Wedgewood completely volatilizes the diamond, producing carbonic acid gas. An English experimentalist, however, has recently declared that the gem may be consumed at a red heat, and maintains that he has accomplished this result by enveloping the stone in certain alkalies.

It has been admitted by eminent geologists that the diamond proceeded from the slow decomposition of vegetable material, and even animal matter, as the requisite carbon could be obtained from either source. But they have also strenuously maintained that the gem was formed under the same conditions of heat as produced the metamorphism of argillaceous and arenaceous schists, these schists being supposed to have once been altered from shales impregnated with carbonaceous substances of organic origin. To this theory the revelations of the microscope offer decisive objections, since this instrument shows that there has been no action of heat in the formation of the stone, for the vegetable remains often detected in the interior of the mineral forbid the development of any considerable degree of caloric. Therefore, as there is no evidence of the influence or effect of heat upon these organic matters within the diamond, the theory must be abandoned.

Geologists have been, perhaps, too tenacious in their views of the origin of many of the rocks that compose the earth’s crust, and especially in maintaining that many crystalline rocks are as old as the dawn of creation. We know that some of these minerals may be produced artificially at the present day, and that the forces that arranged all rocks of a high molecular organization are still in force.

We sometimes speak of old crystalline rocks with the inference that their age is beyond comparison, and therefore undetermined. Yet the microscope is constantly lessening the force of these views by revealing prodigious numbers of minute and animal forms in fossil condition in various kinds of crystalline rocks.

We also observe that various forms of silex have been deposited on the earth in recent periods of its history, and even since the appearance of animal life, for we find their remains transformed into agate. Thus it is evident that nature still possesses the power to deposit certain forms of mineral substances.

Arago and Biot, reasoning from the energy of the refractive power of the diamond, were inclined to believe that it contained hydrogen. Sir Humphrey Davy suspected the presence of oxygen, but sought for it in vain after many careful experiments. Chaucourtois, however, deriving a theory from chemical results, came to the view that the stone is derived by the humid process from a hydrocarburet. Reasoning from the process of forming sulphur from hydro-sulphuretted emanations, he believed that in the humid oxidation of a carburetted hydrogen the hydrogen is oxidized, while part of the carbon becomes carbonic acid, and the rest remains as carbon and may crystallize into diamond.

Supposing this hypothesis to be correct, where do you find the required materials for the formation of the diamond? the reader may ask. At the bottom of these lagoons the decomposition of organic matter furnished abundant means for the production of the gem. Carbonic acid is everywhere produced from the decomposition of animal and vegetable matter. It is constantly evolved from the earth, and has the property of decomposing many of the hardest rocks. It is the cause of that mysterious decay which Dolomieu called “La maladie du granite.”

In carburetted hydrogen we have the united force of two of the most active substances known as organogens, or generators of organic bodies. But of the vast range of their properties, their affinities, and their interior changes we are still profoundly ignorant. We may, however, easily recognize the fact that their combinations and also almost every other chemical compound may be decomposed by electricity or galvanism.

Here then we have a clew, though perhaps distant, to the formation of the gem. Is not the production of drops of water by passing the electric spark through a mixture of hydrogen and atmospheric oxygen suggestive of the manner in which the diamond might be formed from carburetted hydrogen? It is true this experiment in the laboratory has failed to produce the transparent and crystalline form of carbon, although it has thrown down the element in an amorphous state. This failure is by no means decisive, for many of the simple acts of nature are beyond the imitative power of man.

And then again the chemist may exclaim, “How is it possible for the gem to be produced in this manner, when the combination of these elementary bodies is always or nearly always attended with the development of a considerable degree of heat, while the diamond contains at times germs of organic matter? Would not these organic remains be destroyed during this process? On the contrary, they do not exhibit the least trace of the effect of combustion or even heat, and are as well defined as the insects in the fossil resins.” In reply we will point to the formation of fulgurites through the agency of the lightning without the evolution of heat.