YELLOW FEVER.

WE published, last week, some extracts from the personal narrative of Mesns Humboldt and Bompland, respecting the contagion of this disease M. Humboldt proceeds in his pertinent observations on this subject, by citing a series of pathological facts, for the judgment of his readers The well-known and acknowledged accuracy of this traveller, induces us to consider all his facts as authentic

After mentioning the mystery attending the doctrine of contagion, he enquires how we can explore why during the eighteen years which preceeded the year 1794, there was not a single instance of Yellow-Fever at Vera-Cruz, though the concourse of unseasoned Europeans and of Mexicans from the interior was very considerable; though the sailors indulged in the same excesses with which they are still reproached, and though the town was not so clean as it has been since the year 1800?

The following is the series of pathological facts, considered in their greatest simplicity.

When a great number of persons, born in a cold climate, arrive at the same time in a port of the torrid zone, not particularly dreaded by navigators, the typhus of America begins to appear.

Those persons have not had the typhus during their passage; it manifests itself among them only on the very spot.

Is the atmospheric constitution changed? or does a new form of disease display itself among individuals, whose irritability is highly increased?

The typhus soon begins to exert its ravages among the Europeans, born in more southern countries.

If it propagate itself by contagion, it seems surprising, that in the towns of the equinoctial continent it does not attach itself to certain streets; and that immediate contact does not augment the danger, any more than seclusion diminishes it.

The sick, when removed to the inland country, and especially to cooler and more elevated spots, to Xalappa, for instance, do not communicate the typhus to the inhabitants of those places, either because it is not contagious in it’s nature, or that the predisposing causes are not the same as in the regions of the shore.

When there is a considerable diminution of the temperature, the epidemy usually ceases, even on the spot where it first appeared.

It again begins at the approach of the hot season, and sometimes long before; though during several months there has been no sick person in the harbour, and no ship has entered it.

The typhus of America appears to be confined to the shore, either because those persons who bring the disease disembark there, and goods supposed to be impregnated with deleterious miasmata are there accumulated; or because on the seaside gaseous emanations of a particular nature are formed.

The aspect of the places where typhus exerts it’s ravages seems often to exclude all idea of a local or endemical origin.

It has been seen to prevail in the Canaries, the Bermudas, and among the smaller West India Islands, in dry places formerly distinguished for the great salubrity of their climate.— Examples of the propagation of the yellow fever in the inland parts of the torrid zone appear very doubtful; this malady may have been confounded with remitting bilious fevers.

With respect to the temperate zone, in which the contagious character of the typhus of America is more decided, the disease has indubitably spread far from the shore, even into very elevated places. exposed to cool and dry winds, as in Spain, at Medina-Sidonia, at Carlotta, and the city of Murcia.

That variety of phenomena, which the same epidemic exhibits, according to the difference of climates, the union of predisposing causes, it’s shorter or longer duration, and the degree of it’s exacerbation, should render us extremely circumspect in tracing the secret causes of the American typhus.

An enlightened observer, who, at the time of the violent epidemics in 1802 and 1803, was chief physician to the colony of St. Domingo, and who has studied that disease in the Island of Cuba, the U. States and Spain, Mr. Bailly, thinks like me, that the typhus is very often, but not always, contagious.’

Since the yellow fever has made such cruel ravages in La Guayra, the want of cleanliness in that little town has been exaggerated, like that of Vera Cruz, and of the quays or wharfs of Philadelphia.

In a place where the soil is extremely dry, destitute of vegetation, and where a few drops of water scarcely fall in seven or eight months, the causes, that produce what are call ed miasmata, cannot be very frequent.

The streets of La Guayra appeared to me in general to be tolerably clean. with the exception of the quarter of the slaughter houses.

The sea side has no beach, on which the remains of fuct and of Molluscæ are heaped up; but the neighboring coast, which stretches to the east towards Cape Codera, and consequently to the windward of La Guayra, is extremely unhealthy.

The yellow fever and the black vomit cease periodically at the Havana and Vera Cruz, when the north winds bring the cold air of Canada toward the Gulf of Mexico.

But from the extreme equality of temperature, which characterizes the climates of Porto-Cabello, La Guayra, New Barcelona, and Comana, it may be feared, that the typhus will there become permanent, when ever, from a great concourse of strangers, it has acquired a high degree of exacerbation.

Happily the mortality has diminished since the treatment of this epidemic has been varied, according to the character it presents in different years; and since the different stages of the disease have been better studied, which are recognized by symptoms of inflammation, and of ataxy or debility.

It would, I think, be unjust to deny the success, which the new system of medicine has obtained over this terrible scourge; yet the persuasion of this success has not made much progress in the colonies.

It is there said pretty generally, ‘that the physicians now explain the course of the disease in a more satisfactory manner than they did formerly, but that they do not cure it better: that heretofore the patient was left to die slowly, taking no other remedy than an infusion of tamarinds; and that in our days a more active practice carries him to the grave in a more direct and expeditious manner.’

This opinion is not founded upon an accurate knowledge of what was done formerly in the West India Islands.— The voyage of Father Labat sufficiently demonstrates, that in the beginning of the 18th century the physicians of the West Indies did not suffer the sick to die so tranquilly, as seems to be supposed.

They did not then kill by emetics, bark, and opium, employed in two large doses, and unseasonably;—but by frequent bleedings, and the abuse of purgatives.

The physicians indeed seemed so well aware of the effects of their treatment that they had the candour ‘to present themselves at the bed-side of the sick, accompanied at their first visit by a confessor and a notary.’ At present, in neat and well conducted hospitals, they often succeed in reducing the number of deaths to eighteen or fifteen in a hundred, and even a little less.

But whenever the sick are crowded together, the mortality increases to one half, or even to three quarters, of which the French army in St. Domingo afforded an example in 1802.