Letter from M. Humboldt to C. Delambres, one of the perpetual Secretaries of the National Institute .

From Annales du Museum d’Histoire Naturelle, No. 8.

my respected friend, Lima, Nov. 25, 1802.

I have just arrived from the interior of a country where in a large plain I made experiments on the small horary variations of the magnetic needle; and I learn, with regret, that the frigate Astigarraga, which was not to set out before the end of a fortnight, has hastened her departure for Cadiz, and will sail this very night.

This is the first opportunity we have had during five months of writing to Europe from the solitude of the South Seas; and the want of time renders it impossible for me to write as I ought to the National Institute, which has given me the most affecting marks of the interest and kindness with which it honours me. A few days before my departure from Quito for Jaën and the river Amazon, I received the letter dated Pluviose 9th, addressed to me, through you, by that illustrious body.

This letter employed two years to reach me in the Cordillera of the Andes: I received it the day after a second excursion which I made to the crater of the volcano of Pinchincha to carry thither a Volta’s electrometer, and to measure the diameter of it, which I found to be 752 toises, while that of Vesuvius is only 312. This reminded me that on the summit of Guaguapichincha, where I have often been, and which I love as classical ground, La Condamine and Bouguer received their first letter from the ci-devant academy; and I figure to myself that Pinchincha, si magna licet componere parvis, is fortunate to philosophers.

It is impossible for me to express the joy with which I read that letter of the Institute, and the repeated assurances of your remembrance.

How agreeable it is to know that one lives in the memory of those whose labours continually tend to favour the progress of the human mind!

In the deserts of the plains of the Apure, in the thick forests of Casiguiare and of the Oronoko, every where, in short, your names have been present to me; and, while reviewing the different periods of my erratic life, I stopped with pleasure on that of the years 6 and 7, when I lived among you, and when Laplace, Fourcroy, Vauquelin, Guyton, Chaptal, Jussieu, Desfontaines, Hallé, Lalande, Prony, and you in particular, loaded me with kindness in the plains of Lieusaint.

Receive together the homage of my tender attachment and of my constant gratitude.

Long before I received the letter which you wrote to me in your quality of secretary to the Institute, I successively addressed to the Class of the Physical and Mathematical Sciences three letters, two from Santa-Fé di Bogota, accompanied with a work on a genus of cinchona; that is to say, specimens of seven kinds of bark, with coloured drawings of these vegetables; the anatomy of the flower so different by the length of its stamina, and the skeletons carefully dried.

Dr. Mutis, who showed me a thousand marks of kindness, and for whose sake I went up the river in forty days, gave me a manuscript of nearly a hundred magnificent drawings representing new genera, and new species of his Flora of Bogota. I have thought that this collection, as interesting to botany as remarkable for the beauty of the colouring, could not be in better hands than in those of Jussieu, Lamarck, and Desfontaines; and I have presented it to the National Institute as a small mark of my attachment.

This collection and cinchona were sent off for Carthagena of the Indies about the month of June this year; and Dr.

Mutis took upon him to transmit them to Paris.

A third letter for the Institute was dispatched from Quito with a geological collection of the productions of Pinchincha, Catopaxi, and Chimborazo. It is distressing to remain under a melancholy uncertainty in regard to the arrival of those objects, as well as to that of the collection of rare seeds, which three years ago I addressed to the Jardin des Plantes at Paris.

Want of time at present will not allow me to give you an account of my travels and occupations since our return from Rio Negro.

You know that at the Havannah we received the false intelligence of the departure of captain Baudin for Buenos Ayres.

Faithful to the promise which I made of joining him wherever I could, and persuaded that I should be more useful to the sciences by uniting my labours to those of the naturalists who accompanied captain Baudin, I did not hesitate a moment to sacrifice the little glory of finishing my own expedition; and I immediately freighted a small vessel to Bataban, that I might proceed to Carthagena of the Indies.

This short passage was lengthened more than a month by stormy weather; the winds had ceased in the South Seas, where I expected to find captain Baudin; and I entered on the difficult route to Quito by Honda, Ibagué, the passage of the mountain of Quindin, Popayan, and Pastos.

My health continued in a wonderful manner to withstand the change of temperature to which one is exposed in this route, descending every day from snowy regions of 2460 toises in height to scorching valleys where the thermometer does not fall below 26° or 24°.

My companion Bonpland, whose knowledge, courage, and immense activity were of great assistance to me in my botanical researches and comparative anatomy, was afflicted for two months with a tertian fever.

The season of the great rains came upon us in the most critical passage, the high plain of Pastos, and after a journey of eight months we arrived at Quito, where we learned that captain Baudin had pursued his voyage from west to east by the Cape of Good Hope.

Accustomed to misfortunes, we consoled ourselves with the idea of having made so great sacrifices for an intention of doing good: casting our eyes on our herbals, our barometric and geodesic measurements, our drawings, and our experiments on the air of the Cordillera, we did not regret our having traversed that country, a great part of which has never been visited by any naturalists.

We were sensible that man ought never to depend on any thing but what is produced by his own energy.

The province of Quito, the highest land in the world, and torn by the grand catastrophe of the 4th of February 1797, furnished us with a vast field for physical observations.

Volcanoes so enormous, the flames of which often rise to the height of 500 toises, have never been able to produce a drop of liquid lava; they vomit up fire, sulphurous hydrogen gas, mud, and carbonated argil.

Since 1797 this whole part of the world has been in agitation; we every moment experience frightful shocks, and the subterranean noise in the plains of Rio Bamba resembles that of a mountain crumbling to pieces under our feet.

The atmospheric air and moistened earth (all these volcanoes are in decomposed porphyry) appear to be the grand agents of these combustions and these subterranean fermentations.

It has hitherto been believed at Quito that 2470 toises is the greatest height at which men could resist the rarity of the air.

In the month of March 1802 we spent some days in the large plains which surround the volcano of Antisana at 2107 fathoms, where the oxen, when hunted, often vomit up blood.

On the 16th of March we found out a passage over the snow, a gentle acclivity, on which we ascended to the height of 2773 toises.

The air there contained 0·008 of carbonic acid, 0·218 of oxygen, and 0·774 of azote.

Reaumur’s thermometer was only at 15°; it was not at all cold, but the blood issued from our lips and eyes.

The situation did not permit me to make a trial of Borda’s compass but in a grotto lower down at the height of 2467 toises: the intensity of the magnetic forces was greater at that height than at Quito in the ratio of 230 to 218: but it must not be forgotten that the number of oscillations often increases when the inclination decreases, and that this intensity is increased by the mass of the mountain, the porphyry of which affects the magnet.

In the expedition I undertook on the 23d of June 1802 to Chimborazo, we proved that with patience it is possible to sustain a greater rarity of the air.

We ascended 500 toises higher than Condamine (on Carazon), and on Chimborazo we carried our instruments to the height of 3031 toises, where we saw the barometer fall to 13 inches 11·2 lines: the thermometer was at 1·3° below zero.

We still bled at the lips; our Indians deserted us as usual; C. Bonpland, and M. Montufar, son of the marquis de Salvalegre of Quito, were the only persons who remained.

We all experienced an uneasiness, debility, and desire to vomit, which certainly arose as much from the want of oxygen in these regions as from the rarity of the air.

At that immense height I found only 0·20 of oxygen.

A frightful chasm prevented us from reaching the summit of Chimborazo, of which we were within 236 toises.

You know that a great uncertainty still prevails in regard to the height of this colossus, which La Condamine measured only at a very great distance, assigning to it the height of nearly 3220 toises, whereas Don Juan makes it 3380 toises; nor does this difference arise from the different heights which these astronomers adopted for the signal of Carabura. I measured in the plain of Tapia a base of 1702 metres.

Pardon me if I speak sometimes of toises and sometimes of metres, according to the nature of my instruments.

You know that in publication every thing may be reduced to the metre and centigrade thermometer.

Two geodosic operations gave me for Chimborazo 3267 toises above the level of the sea; but the calculations must be rectified by the distances of the sextant from the artificial horizon and by other circumstances.

The volcano of Tunguragua has decreased a great deal since the time of La Condamine: instead of 2620 toises I found no more than 2531; and, in my opinion, this does not arise from an error in the operations, because in my measures of Cayambe, Antisana, Cotopaxi, and Iliniza, I seldom differ ten or fifteen toises from the results of La Condamine and Bouguer.

The inhabitants of these unfortunate countries all say that Tunguragua has visibly decreased in height: on the other hand, I find that Cotopaxi, which has been subject to such immense explosions, is of the same height as in 1744, or rather somewhat higher.

But the stony summit of Cotopaxi indicates that it is a chimney, which resists and retains its figure.

The operations we made from January to July in the Andes of Quito gave to their inhabitants the dismal intelligence that the crater of Pinchincha, which La Condamine saw full of snow, burns again; and that Chimborazo, which was thought to be so peaceable and innocent, has been a volcano, and perhaps will one day be so again.

We found burnt rocks and pumice-stone at the height of 3031 toises.

It will be unfortunate for the human race if the volcanic fire, for it may be said that the whole high land of Quito is one volcano with several summits, should force a passage through Chimborazo.

It has often been said that this mountain is granite, but a single atom of it is not to be found: it is porphyry, here and there disposed in columns inclosing vitreous feld-spar, corncerre and olivin.

This stratum of porphyry is 1900 toises in thickness.

On this subject I could mention a polarizing porphyry which we discovered at Voisaco near Pasto; a porphyry which, analogous to the serpentine I described in the Journal de Physique, has poles without attraction.

I might mention other facts relative to the grand law of the parallelism of the strata, and of their enormous thickness near the equator: but this is too much for a letter, which perhaps will be lost; and besides, I shall recur to this subject another time: I shall only add, that besides the elephants teeth which we sent to C. Cuvier from the land of Santa- Fé, 1350 toises in height, we have preserved for him others more beautiful; some of the carnivorous elephant, and others of a species a little different from those of Africa, brought from the valley of Timana, the town of Ibarra, and from Chili.

Here then we have confirmed the existence of that carnivorous monster from the river Ohio from 50° northern latitude to 35° south latitude, I spent a very agreeable time at Quito.

The president of audience baron de Carondelet loaded us with kindness, and for three years I have not once had reason to complain of the agents of the Spanish government, which have every where treated me with a delicacy and distinction of which I must ever retain a grateful remembrance.

How much the times and manners have changed!

I have paid particular attention to the pyramids and their foundation, which I do not think at all deranged in regard to the mill-stones (pierres molaires).

A generous individual, a friend to the sciences, and to those men who have done honour to them, such as La Condamine, Godin, and Bouguer, the marquis de Salvalegre, at Quito, thinks of reconstructing them; but this leads me too far.

After passing Assonay and Cuenca, where they gave us bull-fights, we pursued our way by the Oxa to complete our labours on cinchona.

We then spent a month in the province of Jaën de Bracamorros and among the Pongos of the river Amazon, the banks of which are ornamented with the andiva and buganvillæa of Jussieu. It appeared to me of importance to fix the longitude of Tomependa and Chucungat, where Condamine’s chart begins, and to connect these points with the coast.

La Condamine was able to determine the longitude only of the mouth of the Napa: time-keepers were not then in existence, so that the longitude of these countries requires a great many changes.

My chronometer by Louis Berthoud does wonders; as I see by making observations from time to time on the first satellite, and comparing point for point my differences of meridian with those found during the expedition of M. Fidalgo, who by order of the king performed trigonometrical operations from Cumana to Carthagena.

From the river Amazon we crossed the Andes at the mines of Hualgayoc, which produce a million of piastres per annum, and where the mine of gray argentiferous copper is found at the height of 2065 toises.

We descended by Casamasca (where in the palace of Atahualpa I delineated the arches of the Peruvian vaults) to Truxilla, proceeding thence by the deserts of the coast of the South Sea to Lima, where for one-half of the year the heavens are obscured by thick vapours.

I hastened to Lima, that I might observe there the transit of Mercury on the 9th of November 1802.

Our collections of plants, and the drawings which I made in regard to the anatomy of genera, agreeably to the ideas communicated to me by Jussieu in conversations in the Society of Natural History, have greatly increased by the riches which we found in the province of Quito, at Loxa, at the river Amazon, and in the Cordilleras of Peru.

We found a great many of the plants seen by Joseph de Jussieu; such as the lloqua affinis, the quillajae, and others.

We have a new species of jussiæa which is charming, colletia, several passifiores, and the loranthus in a tree of sixty feet of height.

We are particularly rich in palms and gramineous plants, on which C. Bonpland has made a very extensive work.

We have at present 3784 very complete descriptions in Latin, and nearly a third more of plants in herbals which for want of time we have not been able to describe.

Of every vegetable we can indicate the rock where it resides, and the height in toises at which it grows; so that in our manuscripts will be found very correct materials for the geography of plants.

To do still better, I and Bonpland have often described the same plant separately.

But two-thirds and more of the descriptions belong to the assiduity of Bonpland alone, whose zeal and devotion for the sciences cannot be too much admired.

Jussieu, Desfontaines, and Lamarck, have in him formed a pupil who will do great things.

We compared our herbals with those of Dr. Mutis, and we consulted a great many books in the immense library of that great man.

We are convinced that we have a great many new genera and species, but much time and labour will be required to determine what is really new.

We shall bring with us also a siliceous substance analogous to the tabascher of the East Indies, which M. Macé has analysed.

It exists in the knots of a gigantic gramineous plant which is confounded with the bambou, but which in its flower differs from the bambusa of Schreiber. I do not know whether Fourcroy has received the milk of the vegetable cow, a tree so called by the Indians. It is a milk which when treated with nitric acid gave me a caout-chouc of a balsamic odour, but which, instead of being caustic and hurtful like all vegetable milks, is nourishing, and agreeable to drink.

We discovered it in the road to Oronoko, in a plantation, where the negroes drink a great deal of it. I have sent also to Fourcroy by the way of Guadaloupe, as well as to sir Joseph Banks by Trinidad, our dapiché, or white oxygenated caout-chouc, which exudes from the roots of a tree in the forests of Pimichin in the most remote corner of the world towards the sources of the Rio Negro.

I shall not go to the Philippines. I shall proceed to Europe by Acapulco, Mexico, and the Havannah; and I hope to have the pleasure of seeing you at Paris in September or October 1803.

Health and respect, Humboldt.

P. S. I shall be at Mexico in February, and at the Havannah in June.