transition to precious stones. The separated earth remains composed of little channels, or tubes, made full of holes by the evaporation of the salts and oils.

The 10th collection consists of earths, sands, and gravels; the 11th collection, of salts, fossils, nitres, alums, vitriols; the 12th collection is composed of sulphurs, bitumens, or salts united to a phlogistic.

The earth of metals is, perhaps, a sort of juice, or stony matter. In copper, it appears with a microscope as if it were composed of little rubies; in pewter, it is chrystalline; and it is talc in lead.

This earth is vitriscible; a strong juice therefore is the base of it, the same that forms the base of sands, gravels, and flints.

Thus the 13th collection of strong juices is a natural consequence of the preceding.

There are various strong juices, which being accidentally united to earths, sands, and gravels, form, in proportion to the mixture, the different species of stones; and perhaps, by the same means, the juices

which constitute the earth of metals, by uniting with proper salts and sulphurs, make the genus and species of metals.

It is from these motives that the Chevalier Baillou, considering, in the first place, the stones in their families, distributes them in the following collections, from which he passes to metals.

These collections are: the 14th. Sandy and gravelly incrustations and stones; 15th. Alabasters and soft serpentine stones; 16th. Granite and porphyry marbles; and the 17th collection is composed of all the different sorts of jaspers; 18th. Of agates, chalce doni, and carnelians; the 19th collection consists of stones of pretended virtues, such as the stellaris stone, the Judaic stones (which are only the echines), the toadstones, the turquoise, &c. and the loadstone, which is the only one among the stones of this class that possesses any real virtue.

There are a great number of metals, in their natural state, which would be put among the number of stones, by judging of them only at first sight. Indeed, scarcely

any but men acquainted with the science can distinguish them.

The pegrite, a stone almost pure, but sulphurous, which frequently contains metal, and which is the forerunner of it, offers a transition very natural, and forms the 20th collection of pegrites or marcassites. The 21st collection consists of metals and other minerals, as they are found in mines.

The strong juice which forms precious stones, is pure; that which colours them is the only thing which unites with it; it is the most perfect substance of metal or mineral, their flower..

The quartzes and fluors form part of the 21st collection; and they have too strong a relation, both in colour and transparency, to precious stones, not to combine with them: they therefore make the transition to the 22d collection of chrystallizations and precious stones attached to their mines, described at length in the body of the work. Relative to this class, the Chevalier establishes two principles: 1st. That each sort of precious stone is formed of a juice peculiar to it, and which produces a configu

ration suitable to its kind; 2d. That the essence of precious stones is not that they should be coloured (that being only an accident); but consists in their hardness, specific gravity, and configuration.

The 23d collection consists of precious stones which are cut; and the 24th and last collection is composed of fictitious stones. From the turquoise to the ruby, all coloured stones may be imitated by means of chemistry; but an examination of their specific gravity and hardness, discovers to the naturalist their true state.

According to the principles of the Chevalier Baillou, we may pass from the ligneous marine plants to the soft marine plants, and thence to botany; and from the crustaceous and testaceous, we may go to fish, amphibious creatures, reptiles, quadrupeds, birds, &c.

88. Two LETTERS FROM Voltaire, relaTIVE TO MYSELF.

Formerly I went frequently to Paris: I saw often many of those who were called "the philosophers." It was particularly

at Madame Geoffrin's, Baron d'Holback's, and d'Alembert's, where they principally assembled. It was there that they silently planned the destruction of religion, of the clergy, the nobility, and the government. From the year 1766, I said to the Bishops who were connected with them, " They "detest you;" to the great noblemen who protected them, "They cannot bear the "splendour of your rank, which dazzles "them;" to the Farmers-General who upheld them, "They envy your riches." These continued, however, to admire, to flatter, and to support them. In 1769 I attempted to give alarm to society, respecting the progress which they had made; and I published a pamphlet at Rome, entituled the Tocsin, which was afterwards reprinted at Turin and at Paris. I there unveiled their destructive designs. The year following, having had occasion to see Voltaire at Geneva, he attacked me about this publication, but I think I extricated myself with tolerable address. I spent the years 1774, 1775, and 1776, in Paris: and published the Tocsin, under the title of an Appeal to