that happiness arose, and in which it centred. Alone, and undistracted by the presence of surrounding friends, the widowed mother approaches in mournful silence the consecrated aisle; where, softly clasped in each other's arms, she sees her beloved children resting in the repose of sleep rather than of death: and gazing on them with intense affection, she feels not sorrow for a while; but, indulging in a dream which almost realizes her past happiness, would fold her treasures to her bosom, were she not too conscious that the cold embrace would dissipate the fond illusion.

SECT. III.

Gems and precious Stones.

If it were the purpose of this treatise to point out the adaptation of external nature to the moral as well as to the physical condition of man, it might be easily shewn, that, however an undue degree of attention to outward ornaments is blamable, a moderate degree of attention is both allowable and right: otherwise, and it is an instance that outweighs all others, it would not have been observed in the decorations of the temple of Solomon, nor in the original ordinations respecting the dress of the Levitical priesthood. Those substances consequently, which are capable of being applied to ornamental purposes, become, in our mode of using them, a test of virtue, in the same manner as our ordinary

clothing, and food, and sleep; all of which, though even necessary to our existence, may be abused by a luxurious indulgence in them. But at present I am no further concerned with the moral part of the question, than to infer that, if an attention to external ornament be not only allowable, but right, we may antecedently expect that materials for its exercise would be provided by nature: and that is indeed the facta.

It would be difficult however to determine which of the three kingdoms, the animal, vegetable, or mineral, is the most prolific source of those beautiful forms and colours which are principally valued as objects of external ornament. We do not indeed observe in any flower that iridescent play of colours which characterises some varieties of the opal and felspar, among minerals; and the plumage of certain birds, and the scales of certain fish, among animals: but in elegance and variety of form, and in splendour and simplicity of colour, the vegetable world will be found to yield neither to the animal nor mineral. Mineral substances, however, from their rarity as well as beauty, are more prized; and from the durability of their substance are more permanently applicable to ornamental purposes than those either of animal or vegetable

a "Wherefore did nature pour her bounties forth?" &c. COMUS, line 726, &c.

origin; and therefore serve better to illustrate the principle of this treatise.

From among those substances which in commercial language are called precious stones, though some so called are not really derived from the mineral kingdom, it is proposed to select the diamond as a preeminent example of the whole class; because, in addition to those properties which render it valuable as an ornamental gem, there are some points in its history which give it a peculiar worth. It will naturally excite the surprise of those, who are unacquainted with the chemical history of this substance, to learn that the purest diamond does not essentially differ from a particular variety of common coal; or from that mineral of which drawing pencils are made, and which is usually, though not with propriety, called plumbago and black lead and yet nothing has been more clearly proved than that equal weights of these several substances, if submitted to the process of combustion, will produce nearly equal proportions of carbonic acid gas; which has already been stated to be a chemical combination of definite proportions of carbon and oxygen; the diamond, which is the purest form of carbon, burning away without leaving any residuum; the other two leaving a very small proportion of ashes, in consequence of their containing foreign

matter.

And here we can hardly fail to notice a very remarkable instance of what may be called the economical provisions of nature. How rarely, and in what small quantities, are the diamond and plumbago found; and how abundantly does coal predominate in many parts of the world! The Borrodale mine of plumbago in Cumberland is the most considerable source of that substance throughout Europe; and the province of Golconda almost alone supplies the whole world with diamonds: and, probably, the accumulated weight of all the plumbago and of all the diamonds, which have ever been derived from those and other sources, would not equal a hundredth part of the weight of coal which is daily quarried in Great Britain. Suppose now that the case had been reversed; and what would have been the consequence? diamond and plumbago, though really combustible substances, yet from their slow combustibility could never have answered, in the place of coal, as a fuel for general purposes; and, on the other hand, without that large supply of coal which nature has provided, what would have become of the domestic comforts and commercial speculations of the greater part of Europe, during the two last centuries?

The value of the diamond is not derived solely from its transparency and lustre. Its remarkable hardness is another and a most useful pro

perty belonging to it: for, in consequence of its great degree of hardness, it is capable of cutting and polishing not only the hardest glass, but even the hardest gems: and if we consider how useful a substance glass is, how universally employed as a means of at the same time admitting light and excluding the air from the interior of our houses; but that in consequence of its hardness and brittleness it would with great difficulty be divided by any common mechanical instrument, so as accurately to fit the frames in which it is fixed for the above purposes, we at once see the value of a substance which easily and readily accomplishes that end. A small diamond no larger than a mustard seed, brought to a point and fixed in a convenient handle, enables the glazier to cut a plate of glass into pieces of any shape that he pleases: and the same instrument will serve his daily use for many successive years. Nor is it among the least of the glories of this gem, that it gave occasion to that remarkable conjecture of sir Isaac Newton respecting its chemical nature. That philosopher having observed, that the refractive power of transparent substances is in general proportional to their density; but that, of substances of equal density, those which are combustible possess the refractive power in a higher degree than those which are not, concluded from a comparison of the density and refractive power