Letter from C. Humboldt to C. Fourcroy, Member of the French National Institute.

Cumana, October 16, 1800.

The capture of the island of Curacao, by the English and the Americans, having obliged the agent of the republic, C. Bressot, and general Jeannet to re-embark their troops, in order to return to Guadaloupe, they have put into this port for want of provisions; and though they intend to remain only twenty-four hours, I have endeavoured to collect for you some objects worthy of your attention, and which I hope will reach you in safety.

You are well enough acquainted with the nature of my travels, and the difficulty and expense attending conveyance in the centre of a vast continent, to know that my object is rather to collect ideas than things.

A society of naturalists sent out by government, accompanied with painters, collectors, packers, &c., might be able to embrace all the detail of the descriptive part of natural history, and, no doubt, would do so; but a private person, of a very moderate fortune, who undertakes a voyage round the world, ought to confine himself to objects more interesting.

To study the formation of the globe, and the strata which compose it; to analyse the atmosphere; to measure, with the most accurate instruments, its elasticity, its temperature, its humidity, its electric and magnetic charge; to observe the influence of climate on the animal and vegetable oeconomy; to compare, on a grand scale, the chemistry and physiology of organized beings; -- such is the labour which I have proposed.

But, without losing sight of this principal object of my voyage, you may readily conceive that, with much zeal and a little activity, two men, who traverse an unknown continent, may at the same time collect a great many things, and make a great many observations.

During the sixteen months we have been traversing the vast territory situated between the coast, the Orenoquo, Rio- Nigro, and the river of the Amazons, C. Bonpland has dried, with duplicates, more than six thousand plants.

I have described with him on the spot twelve hundred species, great part of which appeared to us to belong to genera not described by Aublet, Jacquin, Mutis, or Dombey.

We have collected insects, shells, and different kinds of wood proper for dyeing; we have dissected crocodiles, lamantins, apes, and the gymnotus electricus, the fluid of which is absolutely galvanic and not electric; and have described a great many serpents, lizards, and fish.

I have made drawings of a great number of objects; in a word, I flatter myself that if I have erred it is rather through ignorance than want of activity.

What enjoyment to live in the midst of these riches of nature, so majestic and grand!

Behold, then, the dearest and most ardent of my wishes gratified!

Amidst the thick forests of the Rio-Nigro; surrounded by ferocious tygers and crocodiles; my body tormented with the stings of the formidable moskitos and ants; having had for three months no other aliment than water, bananas, and manioc, among the Otomaqua Indians, who eat earth; or on the banks of the Casquiara, under the equator, where, in the course of a hundred and thirty leagues, no human being is seen; -- in all these embarrassing situations I never repented of my undertakings:

my sufferings have been great, but they were only momentary.

When I left Spain I intended to proceed directly to Mexico, thence to Peru and the Philippines; but a malignant fever, which broke out in our frigate, induced me to remain on this coast of South America; and, thinking it possible to penetrate thence into the interior, I undertook two journeys, one to the missions of the Chayma Indians of Paria, and the other to that vast country situated to the north of the river of the Amazons, between Popayan and the mountains of the French part of Guyana.

We twice passed the grand cataracts of the Orenoquo, and those of Atures and Maypura, in lat. 50° 12' and long. 5° 39', W. dep. from Paris 4° 43' and 4° 41' 40".

From the mouth of the Guaviara and the rivers Atabapo, Temi, and Tuamini, I caused my pirogua to be carried by land as far as the Rio-Nigro, while we followed on foot through forests of Hevea, Cinchona, and Canella Wintertona. I descended the Rio-Nigro as far as Saint Carlos that I might determine its longitude by Berthoud's time-keeper, with which I am still well satisfied.

I ascended the Casquiara inhabited by the Ydapaminares, who eat nothing but ants dried in the smoke.

I penetrated to the sources of the Orenoquo, even beyond the volcano of Duida, or as far as the ferocity of the Guaica and Guaharribo Indians would permit me to venture, and I descended the whole of the Orenoquo, by the force of its current, as far as the capital of Guyana; performing a journey of 500 leagues in twenty-fix days, without counting those on which we stopped.

The error in the latitude (d'Anville's chart) is more than two degrees, as it had never been determined by astronomical instruments.

My health has withstood all the fatigues of a journey of more than 1300 leagues; but my poor companion, C. Bonpland, had nearly fallen a victim to his zeal and devotion for the sciences.

After our return, he was attacked by a violent fever, accompanied with a dangerous vomiting; which, however, was speedily cured.

The river of the Amazons has been inhabited for 200 years by Europeans; but on the Orenoquo and the Rio- Nigro, it was only about thirty years ago that the Europeans ventured to form a few settlements beyond the cataracts.

Those which exist do not comprehend above 1800 Indians, from the eighth degree to the equator; and there are no other whites than six or seven missionary monks, who did every thing they could to facilitate our journey.

From St. Thomas, the capital of Guyana, lat 8° 8' 24", long. 4° 25' 2", we crossed once more the great desert called Elanos, inhabited by wild cattle and horses.

I am now employed in constructing a map of the country through which I have travelled.

I have been so fortunate as to make astronomical observations in fifty-four places.

I observed at Caraccas, Cumana, and Tuy, twelve eclipses of the satellites of Jupiter; an eclipse of the sun on the 28th of October 1799.

By these means, and the chronometer, I flatter myself I shall be able to give a very exact map.

We shall embark here at length for the Havannah, from which we shall proceed to Mexico. --

Such is the summary of my travels.

I know that you, Chaptal, Vauquelin, Guyton, are all interested in my fate; and for that reason I am not afraid of tiring you.

We have scarcely any communication here with Europe. I have often attempted to write to you, as well as to our friends Vauquelin and Chaptal. I have sent you some experiments on air, and the cause of miasmata.

I have sent to Delambre and Lalande, extracts from my small astronomical observations.

Have any of these reached the place of their destination?

By the consul of the republic at Saint Thomas I transmitted to you the milk of a tree which the Indians call the cow, because they drink this milky juice, which is not at all prejudicial, but exceedingly nourishing.

By the help of the nitric acid I have made caoutchouc, and I mixed soda with that destined for you, according to the principles which you yourself fixed.

In the month of January last we sent, by the corvette Philippina, a collection of seeds for the Jardins des Plantes at Paris.

We know they have arrived, and must have been delivered to citizens Jussieu and Thoum by the ambassador of the republic at Madrid.

By the flag of truce, which we expect here from Guadaloupe, the musaeum will receive other articles; for at present we must be fatisfied with presenting you a few objects for your chemical analysis.

I have procured for you the curare, or celebrated poison of the Indians on the Rio-Nigro.

I undertook a journey to Enneralda on purpose to see the liane, which produces this juice, but unfortunately we found it without flowers; and to see the method practised by the Catarapeni and Maquiritures Indians for making this poison.

I shall give you, some other time, a more ample description of it. I shall only add, that I send you the curare in a box of tin plate, and the branches of the plant maracury, which produces the poison.

This liane grows, but not in great abundance, among the granitic mountains of Guandia and Yumariquin, under the shade of the theobromacacao and the caryocar.

The Indians take off the epidermis and make an infusion of it cold, having first expressed the juice; they then leave the water over the epidermis half expressed, and afterwards filter the infusion.

The filtered liquor is yellowish: it is then baked, and concentrated by evaporation and inspissation to the consistence of molasses.

This matter contains already the poison, but not being sufficiently thick to daub over the points of their arrows, they mix it with the glutinous juice of another tree, which they call kiracaguero.

This mixture is again baked till the whole is reduced to a brownish mass.

You know that the curare is taken internally as a stomachic: it is not noxious but when it comes into contact with the blood, which it deoxydates.

It is only a few days ago that I began to make experiments upon it, and I have found that it decomposes atmospheric air. I beg you will try to de-oxydate with it the metallic oxyds, and that you will examine whether the experiments of Fontana were properly made.

This box, and the other articles announced here, have not yet reached C. Fourcroy.

I add to the curare and the marecury, the dapitche, the leche de pindare, and the earth of the Otomaquas.

The dapitche is a state of the elastic gum, which, is, no doubt, unknown to you.

We discovered it in a place where there is no hevea, in the marshes of the mountain of Javita, lat. 2° 5', which are samous on account of the terrible serpents, of the boa kind, found in them.

Among the Pormisano and Paragini Indians we saw musical instruments made of the caoutehouc, and the inhabitants told us they found it in the earth.

The dapitche or zapir is really a spongy white mass found under the roots of two trees, which appeared to us of a new genus, the jacio and the curvana, and of which we shall one day give a description.

The juice of these trees is a very aqueous milk, but it appears that it is a malady in these trees to lose the juice by the roots.

This discharge causes the tree to perish, and the milk coagulates in the moist earth, where it is preserved from the contact of the air. I send you the dapitche itself, and a mass of caoutchouc made from it, merely by exposing it to heat or dissolving it over the fire.

This production, and the milk of the cow, in your hands, will serve to throw new light on this substance, so curious in a physiological point of view.

The leche de pindare, which is the dried milk of a pindartree, is a natural white varnish.

The Indians cover their vessels and tacuma with this milk when it is fresh.

It dries speedily, and forms a very beautiful varnish; but, unfortunately, it becomes yellow when dried in a large mass; and it is in this state that I send it to you.

In regard to the earth of the Otomaquas, I must observe that this nation, so hideous by the paintings which disfigure their bodies, when the Orenoquo is very high, and they can find no tortoises, for three months eat scarcely any thing but a kind of fat earth.

There are some of them who eat a pound and a half of it per day.

Some of the monks assert that they mix with it the fat of the tails of crocodiles: but this is false.

We found among the Otomaquas stores of the pure earth which they eat: they give it no other preparation than that of burning it slightly, and rendering it moist.

It appears to me astonishing that people can be robust and eat a pound and a half of earth daily, while we find that earth produces a very pernicious effect among children.

My own experiments on earths and their properties, however, give me reason to suspect that they may be nourishing; that is to say, that they may act by affinities.

I add for the musaeum, because it has fallen into my hands, the smoking instrument of the Otomaquas, and a shirt of the Piroas, a neighbouring nation.

This smoking instrument is none of the smallest, as you will see.

It is a kind of plate, on which they place the rasped and rotten fruit of a mimosa, mixed with salt and a little quick-lime.

The Otomaqua holds the plate in one hand and in the other the tube, the two ends of which enter his nostrils, that he may inhale this stimulating tobacco.

This instrument has a historical interest: it is common only to the Otomaquas and the Omeguas, two nations who at present are 300 leagues distant from each other, among whom Condamine saw it. It proves that the Omeguas, who, according to an old tradition, came from Guaviara, may be descended from the Otomaquas, and that the city of Manoa was seen by Phillip de Vure between Meta and Guaviara.

These facts are interesting in regard to the origin of the fable of the Dorado.

The shirt, which one of my people wore for a long time, is the bark of the tree called morima, without any preparation.

You see that shirts grow upon trees in this country, and near the Dorado, where I found no mineral curiosities but talc and a little titanium.

It has been impossible for us to arrange the seeds and plants of the Rio-Nigro destined for Thouin, Jussieu, and Desfontaines, who will not altogether have forgotten me.

We have very uncommon things; for example, new kinds of befaria, new genera of palms; all which we shall soon dispatch, and be assured that we shall not lose sight of the interests of the musaeum.

But alas! captain Baudin has set out, and we are here!

This is very hard and distressing.

We shall perhaps find him in the South Sea.

I beg you will remember me to the respectable members of the National Institute: my respects to Berthollet, Chaptal, Vauquelin, Guyton, Jussieu, Desfontaines, Halley, Delambre, Laplace, Cuvier.

In the letter which I send to Delambre I forgot an eclipse, which I beg you will add to it.

Immersion of the 3d satellite on the 4th of October 1800, at Cumana, at 16 h. 59' 36" mean time.

P. S. Repeat, I beg of you, my request to the Board of Longitude for the Connoissances des Tems.

I regret the death of general Desaix.

What a loss to the republic and all mankind!