From the Boston Gazette.

Humboldt's History of New-Spain.

"The vally in which the city of Mexico stands, is upwards of 6500 feet above the level of the sea.

It is of an oval form, encompassed on all sides by mountains.

It contains several lakes.

The largest is salt.

Formerly it surrounded the city, which was approached only by causeways, constructed in the water.

But, at present, the extent of this lake is diminished, and the city is now on the land, at some distance from the water's edge.

The circumference of the valley is 67 leagues.

"Mexico is undoubtedly one of the finest cities ever built by Europeans in either hemisphere.

With the exception of Petersburgh, Berlin, Philadelphia, and some quarters in Westminster, there does not exist a city of the same extent, which can be compared to the capital of New-Spain, for the uniform level of the ground on which it stands, for the regularity and breadth of the streets, and the extent of the public places.

The architecture is generally of a very pure style, and there are even edifices of very beautiful structure.

The exterior of the houses is not loaded with ornaments.

"The Ballustrades and gates are all of Biscay iron, ornamented with bronze, and the houses, instead of roofs, have terraces like those in Italy, and other southern countries.

"Mexico has been very much embellished, since the residence of the abbe Chappe there in 1769.

The edifice destined to the School of Mines, for which the richest individuals of the country furnished a sum of more than three millions of francks, would adorn the principal places of Paris or London.

Two great palaces [hotels] were recently constructed by Mexican artists, pupils of the academy of fine arts of the capital.

One of these palaces, in the quarter della Traspana, exhibited in the interior of a court a very beautiful oval peristyle of coupled columns.

The traveller justly admires a vast circumference, paved with porphyry flags, and enclosed with an iron railing, richly ornamented with bronze, containing an equestrian statue of king Charles the fourth, placed on a pedestal of Mexican marble, in the midst of the Plaza Major of Mexico, opposite the cathedral, and the viceroy's palace.

However, it must be agreed, that notwithstanding the progress of the arts, within these last thirty years, it is much less, from the grandeur and beauty of the monuments, than from the breadth and straitness of the streets, and much less from its edifices, than from its uniform regularity, its extent and position, that the capital of New Spain attracts the admiration of Europeans.

"Nothing can present a more rich and varied appearance, than the valley, when, in a fine summer morning, the sky without a cloud, and of that deep azure which is peculiar to the dry and rarefied air of high mountains, we transport ourselves the top of one of the towers of the cathedral of Mexico, or ascend the Hill of Chapoltepeck.

A beautiful vegetation surrounds this hill.

Old cypress trunks, of more than 15 and 16 metres in circumference, raise their naked heads above those of the schinus which resemble, in their appearance, the weeping willows of the east.

From the centre of this solitude, the summit of the porphyritical rock of Chapoltpeck, the eye sweeps over a vast plain of carefully cultivated fields, which extend to the very feet of the colossal mountains covered with perpetual snow.

The city appears as if washed by the waters of the lake of Tezeuco, whose basin, surrounded with villages and hamlets, brings to mind the most beautiful lakes of the mountains of Switzerland.

Large avenues of elms and poplars lead in every direction, to the capital; and two acqueducts, constructed over arches of very great elevation, cross the plain, and exhibit an appearance equally agreeable and interesting.

The magnificent convent of Nuestra Sornora de Guadaloupe, appears joined to the mountains of Teypeyacack, among ravines, which shelter a few date and young yucca trees.

Towards the south, the whole tract between San Angel, Tacabaya, and San Augustin de las Cuevas, appears an immense garden of orange, peach, apple, cherry, and other European fruit trees.

This beautiful cultivation forms a singular contrast with the wild appearance of the naked mountains which enclose the valleys among which the famous volcanos of La Puebla, Popocatepetl, and Iztaccicichuatl are the most distinguished.

The first of these forms an enormous cone, of which the crater, continually inflamed, and throwing up smoak and ashes, opens in the midst of eternal snows."