In reflecting upon these phenomena, and in seeking for the causes that led to the creation of the diamond, and sifting down the evidence that science has patiently brought to light, we are naturally led to philosophic musings. It is a singular reflection that much of our commercial greatness is derived from luxuriant vegetations of early ages of the earth’s history. How much pleasure, how many of the comforts of civilization and even the necessities of life, do we owe to the extinct fauna of by-gone ages! Even invalid man, seeking to restore the exhausted fountains of his shattered nature in the waters of some of the sulphur springs, quaffs the life-restoring principles from the mineral and animal _débris_ of the lower ocean of the old red sandstone. Here, then, is a happy adaptation of the vague and empty theory of transmigration of the ancients,--the metempsychosis of Empedocles. Certain elements imprisoned in the earth for ages return again at last to reanimate exhausted man and improve his social life. The same agency in recent times, and by natural though mysterious laws, has produced from similar materials the gem, which seems to be quite as necessary for the superficial wants of mankind as gold or silver. In studying the earth’s history and examining the successive phases of its development, we are insensibly led to the idea that all these stages, seemingly progressive, never retrograde, were for a definite purpose, if not for the exclusive benefit of mankind. For it is only just before the introduction of man that some of the highest orders of vegetation, such as the _Rosaceæ_, appear on the earth. There is certainly a marked intent in the appearance of the pear, the apple, plum, cherry, peach, and other fruits, with the true grasses, late in the tertiary period. We may also trace this suggestive progression in the development of even insect life. In the Silurian age the hum of the insect was unheard; and it was not until the oölitic period that this form of animal life appeared. A fossil gem--the amber--reveals the time of the birth of the insect dearest to man; and it was not until the eocene change that the earth heard for the first time “The soft murmur of the vagrant bee.” May we not also place in the same category of possible intents the late deposition of the diamond? It is not so very strange, after all, when we come to consider the vast field that lies within the range of the argument. CHAPTER V. PHYSICAL PROPERTIES, ETC.