by the name of miasmata are formed, but we are ignorant of their chemical composition. We are no longer permitted to attribute intermittent fevers to the hydrogen accumulated in warm and humid situations; ataxical fevers to ammoniacal emanations; or inflammatory diseases, to an increase of oxygen in the atmospheric air. The new chemistry to which we owe so many positive truths, has also taught us that we are ignorant of many things which we long flattered ourselves we knew with cer. tainty. Whatever be our ignorance respecting the nature of the miasmata, which are perhaps ternary or quaternary combinations, it is not the less certain that the insalubrity of the air of Vera Cruz would be sensibly diminished, if they could but drain the marshes in the neighbourhood of the town; if they could supply the inhabitants with potable water; if the hospitals and church-yards could be removed to a distance *; if frequent fumigations of oxygenated muriatic acid were made in the apartments of the patients, in churches, and especially on board of vessels; and finally, if the walls of the town, which force the population to be concentrated in a small space of ground, and prevent the circulation of air without preventing contraband trade, were to be thrown down. If, on the other hand, the government fall upon the extremity of destroying a town, the building of which has cost so many millions; and if it forces the merchants to settle at Xalapa, the mortality of Vera Cruz will not diminish so much as may at first be believed. No doubt the Negro muleteers or natives of the coast might carry the goods to the farm of l'Encero, which is the superior limit of the vomito, and it would not be necessary for the inhabitants of Queretaro and Puebla to descend to the port for their purchases; but the seafaring people, among whom the vomito commits the most cruel ravages, would be always obliged to remain in the port. The persons who should be forced to remain at Xalapa would in fact be those who are habituated to the climate of Vera Cruz, because for a long time their commercial affairs have fixed them on the coast. We shall not examine in this place the extreme difficulty with which affairs which comprehend an annual capital of 250 millions of livres tournois" can be carried on at so great a distance from the port and magazines; for the beautiful town of Xalapa, where there is a perpetual spring, is more than twenty leagues distant from the sea. If Vera Cruz is destroyed, and a fair established at Xalapa, the trade will of new fall into the hands of a few Mexican families, who will gain immense wealth; and the inferior merchant will be unable to make head against the expence of frequent journies from Xalapa to Vera Cruz, and the double establishment on the mountains and on the coast. . The inconveniences which would be occasioned by the destruction of Vera Cruz have been stated to the viceroy by persons of intelligence; but it has at the same time been proposed to shut up the port during the months of the great heats, and to limit the entry of vessels to winter, when Europeans run no risk of contracting the yellow fever. This appears a very wise measure, when we merely consider the danger incurred by the sea-faring people already in the port, but we must not forget that the same north winds by which the atmosphere is cooled, and by which the germ of infection is extinguished, are also very dangerous to navigation in the gulph of Mexico. If the vessels which annually arrive in the port of Vera Cruz were all to arrive during winter, shipwrecks would be extremely common both on the coast of America and the coast of Europe. Hence, before having re

course to such extraordinary measures, all the means calculated to diminish the insalubrity of a town, the preservation of which is not only connected with the individual prosperity of its inhabitants, but also with the public prosperity of New Spain, should be resorted to.