ing their empire by the fear of physical evil.

"The situation of the new volcano of Jorullo leads to a very curious geological observation. It has already been observed in the third chapter, that there is in New Spain a line of great heights, or a narrow zone included between the Latitudes of 18° 59′ and 19" 12′, in which are all the suminits of Anahuac that rise above the region of perpetual snow. These summits are either volcanoes still actually burning; or mountains, the form of which, as well as the nature of their rocks, renders it extremely probable, that they formerly contained subterranean fire. Setting out from the coast of the Gulf of Mexico, and proceeding westward, we find the peak of Oribaza, the two volcanoes of la Puebla, the Nevado de Toluca, the peak of Tancitare, and the volcano of Colima. These great heights, instead of forming the ridge of the cordillera of Anahuac, and following its direction, which is from S. E. to N. W., are on the contrary in a line perpendicular to the axis of the great chain of mountains. It is certainly worthy remark, that in the year 1759 the new volcano of Jorullo was formed in the continuation of this line, and on

the same parallel as the ancient Mexican volcanoes.

"A view of my plan of the environs of Jorullo will show, that the six large hummocks have risen out of the earth on a vein, that crosses the plain from the cerro of Jas Cuevas to the pichaco del Montero. The new mouths of Vesuvius too are found ranged along a fissure. Do not these analogies give us reason to suppose, that there exists in this part of Mexico, at a great depth within the Earth, a fissure stretching from east to west through a space of 137 leagues [343 miles], and through which the volcanic fire has made its way at different times, bursting the outer crust of porphyritic rocks, from the coasts of the Gulf of Mexico to the South Sea ? Is this fissure prolonged to that little groupe of islands, called by Colluet the Archipelago of Regigedo, and round which, in the same parallel with the Mexican volcances, pumice stone has been seen floating? Naturalists who distinguish the facts offered by descriptive mineralogy from theoretical reveries concerning the primitive state of our planet will pardon me for having consigned these observations to the general Map of New Spain, contained in the Mexican Atlas."

E know from ancient au

thors, as well as from weapons and utensils dug up in modern times, that men in the earliest ages, and even those that succeeded them, employed copper in preference for the fabrication of metallic

utensils and weapons. Thus what Herodotus says of the Massagetæ, who used no iron, and whose weapous and utensils were of copper, is more or less applicable to all the nations of antiquity.

"The great difference in the exP 2

terior

terior characters of the two metals in their crude state leaves no doubt, that men were sooner acquainted with copper, and the method of adapting it to their purposes, than iron. It is probable, that they found copper in large masses, and nearly prepared by nature, as we still meet with it in countries, the mineralogical wealth of which has been little explored. Accordingly in treating the ore by fire they could not fail to observe all the advantages of this metal both with respect to the richness of its produce, and the facility with which it might be forged. Iron, on the contrary, was not so obvious to men's eyes; and the distinguishing of its various ores, with the art of working them, and forming wea pons and instruments of them, could only be the fruit of long experience.

"I shall not avail myself of the numerous testimonies of ancient authors to prove, that copper has been employed in preference to iron, as it is sufficient, to appeal to Homer. All weapons, both offensive and defensive, as swords, spear-heads, helmets, and shields, as well as various domestic utensils, were of copper (xaλxos); though in Homer's time iron (orongos) was used, but less frequently, and hardened by plunging redhot into water. Even when the advantages of iron, and the modes of fabricating it, were well known, men used copper for their weapons; for instance, in the last ages of the republics of Greece and Rome.

"We know, that copper is not fit for the purposes, for which the ancients employed it. When cast it is porous and brittle; and, when forged, too soft. The ancient weapons and utensils being of a hardness, which this metal does not pos

sess, it was long supposed, that the ancients had some method of hardening copper, as we do iron and steel. But chemical analysis has shown the falsity of this opinion; and demonstrated, that these weapons and instruments were not pure copper, but an alloy of this metal with tin, which we call bronze, and which was the aes, brass, of the Romans. The weapons, instruments, and statues, which have been dug out of the ground, evidently prove, that the property of tin to impart bardness and density to the metal alloyed with it was known and employed by the most ancient nations. All these objects occur of bronze, but none of pure copper. It is astonishing, that this practice of imparting to copper, by alloying it with a certain portion of tin, a hardness sufficient for sword-blades and other cutting instruments, should have been so generally fol lowed by the ancients, notwithstanding the want of tin mines. All the tin they used they were obliged to procure from the Cassiterides, the present Cornwall, and the trade was exclusively in the hands of the Phenicians.

"Having had an opportunity of assaying several fragments of metallic antiquities, I conceive it may be of some utility to make public the results, as a supplement to the few accurate analyses hitherto made.

"The fragments to be analysed, being first weighed, were put inic a phial, into which were poured six or eight parts of nitric acid of the specific gravity of 1 22, and digested in a sandheat; till completely dissolved. The contents of the phia! were then diluted with a sufficient quantity of water, and the mixture left to stand, till all the oxide of vin had fallen down, and the azure liquid appeared quite clear. This

the ancients were unacquainted with the art of casting metals, is absolutely false.

"To say nothing of the nature of bronze rendering it incapable of being prepared in any other way, any one may be convinced of this by simple inspection; and if you would have a proof of it in Homer, you need only read the 23d book of the Iliad.

2. Analysis of the metallic alloy of crooked antique knives.

"In several provinces of Germany cutting instruments, shaped like sickles, have been found in dig ging or ploughing the ground; but whether they really were ancient sickles is not determined, as many suppose, that they may have been used as knives in the warm baths. I have selected two of these, found at different places, for analysis.

"One, which was found with various utensils in a garden at Merz, near Mueltord, yielded by analysis, after its crust of grayish rust was removed, tin 15 parts, copper 85.

"The other, found in the island of Rugen, was covered with the common patina, and gave tin 13, copper 87.

3. Analysis of an antique ring.

"I had selected for other inquiries a fragment of an elastic and flexible ring, which was found with some Roman coins in the vicinity of the Rhine. This ring was made with a half-flattened stem, grooved on the outside, and 8 lines broad. Its exterior diameter is 2 inches, its interior 24. It is not soldered, but its extremities are so closed by the elasticity of the metal, that it is difficult to separate them. The colour of the metal, in the parts that have been polished, is very fine. We have no sufficient clew

4. Analysis of a piece of Grecian brass.

appears

"This little fragment, decorated with ornaments, which was found in Sicily in a Grecian tomb, to have been a button, or some other ornament of armour. Its proportions are, tin 11, copper 89.

5. Analysis of antique rivets.

"These rivets were short, and of the thickness of a middle-sized wire. As it was necessary they should be flexible, it was requisite, that the alloy should be in different proportions, that of the tin being dimi nished. This consisted of tin 2:25, copper 97.75,

6. Analysis of an antique cup.

"The great number of antique cups and vases found at different times sufficiently prove, that the ancients possessed the art of reduc ing bronze to thin sheets. The cup. pieces of which were employed for this analysis, was found in a Gre cian tomb near Naples. It has so well resisted rust, that its inside has lost very little of its polish. Being very thin, I expected to fird in it but a small proportion of tin; but I obtained tin 14, copper 86.

"Comparing the proportions of tin found in the present analysis with those of a fragment of an entique mirror, which I had already published in Scherer's Journal, Vol.

VI,

VI. and which consisted of 32 per cent. tin, and a little lead, we find, that the ancients judiciously adapted the proportions of tin and copper to the purposes for which they were required. I conceive it unnecessary to particularize the rest of the analyses I made of pieces of antique bronze: it is sufficient to say, that, except this mirror and the rivets already mentioned, I always found the alloy contained from 9 to 15 per cent of tin.

7. Analysis of the quadriga of

Chios.

"The proportious of the alloy of this masterpiece of antiquity bear no resemblance to those already. mentioned. It has been long asserted, that these horses were the work of Lysippus, contemporary of Alexander, who is known in the history of the arts as the greatest master in the execution of eques triau statues: but sever.l modern connoisseurs dispute this, and say the horses are in too clumsy a style, to have been the work of Lysippus.

"It is admitted however, that they were brought from Chios to Constantinople in the reign of Theodosius I. In 1204, when the croisaders made themselves nisters of that city for the second time, pillaged it, and set it on fire, this quadriga escaped the destruction that befel many ancient works of art. On dividing the plunder, the doge Dandolo destined these horses for the republic of Venice. After his death the podestat Martin Zeno sent them to Venice with other parts of the spoil, and the doge Peter Ziani ornamented with them the entrance to the cathedral of St. Mark. About Bix centuries after, in 1799, they were removed to Paris, and placed at the two entrances of the square

of the Carrousel. Since that time they have been brought together again, and harnessed to a chariot,, to decorate the triumphal arch in that square.

"These four horses were not cast at once, like statues in bronze, but are composed of separate parts, wrought with the chisel, and afterward joined together. The hollows in the hind parts are filled with lead, which has assumed its shining reddish appearance. These parts are gilt: yet the gilding is nearly effaced, though, according to Buonarotti, the gold with which the ancients covered their bronze was to ours as six to one.

me.

"These horses were supposed to be of copper, because this metal takes gilding better than bronze; and I have been enabled to verify the fact on a small piece weighing 40 grains, which was sent From this it appears, that the copper was not absolutely pure, as it contained a little tin; but the oxide of tin obtained from these 40 grs. amounted only to 0.35 of a grain; so that, when reduced to the metallic state, the proportion would be only 7 parts of tin to 993 of copper. This proportion is so small, it may be presumed to have been accidental.

"In our days the use of iron and brass has singularly diminished that of bronze, which was so frequently employed by the ancients. It is now confined to cannons, bells, and statues. But is it not desirable, that our copper vessels should be replaced by vessels of bronze or brass, as they are less liable to oxidation, and to injure the health? This ques tion deserves to be solved by comparative experiments. What ought to induce us to examine this important question is, that the ancients employed only vessels of bronze in