copy of a letter read in the class of physical and mathematical sciences.

Alexander Humboldt to Citizen Delambre, Perpetual Secretary of the National Inſtitute.

From Lima, the 25th November, 1802. my worthy friend,

I JUST arrive from the interior of the country, where I have made experiments on a wide plain on the hourly variations of the magnetic needle, and learn with regret that the frigate Aſtigaragga which was only to have departed in a fortnight, is now going to ſet ſail for Cadiz this very night.

For theſe five months it is the firſt opportunity we have had for Europe in the ſolitary regions on the Pacific Ocean; and want of time renders it impoſſible for me to write as I ought to the National Inſtitute, from which I have juſt received the moſt affecting proofs of the kindneſs with which it honours me. A few days before my departure from Quito for Jaen and the Amazone, I received the letter which that Society addreſſed to me by your hands.

It is dated the 2d Pluvioſe, 9th year, and has taken two years to reach me in the Cordillieras of the Andes.

It came to hand the day after my ſecond expedition to the crater of the volcano of Pichincha, whither I had gone with an electrometer of Volta, and to meaſure the diameter, which I find to be 752 toiſes, while that of Veſuvius is only 312. This reminds me that on the ſummit of Guaguapichincha, (where I have been often, and which I regard as claſſical ground,)

La Condamine and Bouguer received their firſt letter from the ci-devant Academy; and I imagine that Pichincha, ſi magna licet componere parvis, is a lucky ſpot for natural philoſophers.

How ſhall I expreſs to you, Citizen, the ſatisfaction with which I peruſed this Letter of the National Inſtitute, and the repeated aſſurance of your kind remembrance.

How delightful is it to know that we live in the memory of thoſe whoſe labours daily advance the progreſs of the human mind!— In the deſerts of the plains of Apure, in the thick foreſts of Caſiguian and of the Orenoque, every where your names have been preſent to me; and running over in thought the different epochs of my wandering life, I have dwelt with tranſport on thoſe of the 6th and 7th year, when I lived in the midſt of you, and where Laplace, Fourcroy, Vauquelin, Guyton, Chaptal, Juſſieu, Desfontaines, Hallé, Lalande, Prony, and eſpecially you, my generous and affectionate friend, loaded me with kindneſs in the plains of Lieurſaint.

Accept all of you together the homage of my tender attachment and my conſtant gratitude.

Long before I received your letter in your capacity of Secretary to the Inſtitution, I addreſſed ſucceſſively to the Phyſical and Mathematical Claſs, three letters; two from Santa-Fé de Bogota, accompanied with a treatiſe on the genus Chincona, (that is to ſay, ſpecimens of bark of ſeven ſpecies; coloured drawings repreſenting theſe vegetables with the anatomy of the flowers ſo different as to the length of the ſtamina, and ſkeletons dried with care.)

Doctor Mutis, who behaved moſt kindly to me, and for whoſe ſake I went up the river La Madelaine forty days journey, has made me a preſent of more than one hundred magnificent draughts, large folio, giving figures of new genera, and new ſpecies of his manuſcript Flora of Bogota. I thought that this collection, as intereſting for 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 offered it to the National Inſtitute as a feeble mark of my attachment.

This collection and the Chinconas were ſent for Carthagena in South America about the month of June this year: M.

Mutis himſelf took in hand to forward them to Paris.

A third letter for the National Inſtitute was ſent from Quito, with a geological collection of the productions of Pichincha, Cotopaxi, and Chimborazo.— How afflicting is it to remain in a ſad uncertainty concerning the arrival of theſe articles, and of the collections of rare grains which three years ago we directed to the Jardin des Plantes at Paris!

My time is too ſhort to-day to give you an account of my travels and occupations ſince my return from Rio-Negro.

You know that it was at the Havannah we received a falſe report of the departure of Captain Baudin for Buenos-Ayres.— Faithful to my promiſe of joining him wherever I could, and perſuaded I ſhould be more uſeful to ſcience by uniting my labour to that of the naturaliſts who follow Captain Baudin, I did not heſitate a moment to ſacrifice the little glory of finiſhing my own expedition; and I freighted immediately a ſmall veſſel at Batabano, in order to proceed to Carthagena.

Storms retarded this ſhort paſſage upwards of a month, as the gales had ceaſed in the Southern Ocean, where I expected to fall in with Captain Baudin. I entered on the difficult route of Honda, of Ibague, of the paſſage of the mountain of Quindiu, of Popayan, from Paſta to Quito.

My health continued to reſiſt wonderfully well the change of temperature to which one is continually expoſed in this route, deſcending every day from ſnows of 2460 toiſes, to ſcorching valleys, where Reaumur’s thermometer is never below twenty-four or twenty-ſix degrees.

My companion, whoſe knowledge, courage, and immenſe activity have been of the greateſt uſe to me in reſearches on botany and comparative anatomy, Citizen Bonpland, has been ill of the tertianague for the ſpace of two months.

The rainy-ſeaſon overtook us in the moſt critical paſſage, on the flats of the Paſtas, and after a journey of eight months we arrived at Quito, where we learned that Citizen Baudin had taken his route from Weſt to Eaſt by the Cape of Good Hope.

Accuſtomed to diſappointments, we comforted ourſelves with the thoughts of having made ſo great ſacrifices with a good deſign.

On looking at our herbarium, our meaſurements, barometrical and geodeſical, our drawings, our experiments on the air of the Cordillieras, we did not regret having viſited countries, the greater part unknown to naturaliſts.

We felt that man can depend on nothing but what is produced by his own energy.

The province of Quito, the moſt elevated flat in the world, rent by the great cataſtrophe of the 4th February 1797, has opened to us a vaſt field for natural obſervations.

Such enormous volcanoes, whoſe flames riſe often to the height of one thouſand metres, have never produced any lava.

They emit water, hydrogen, ſulphurated gaz, mud, and carbonated argile.

Since the year 1797 the whole of this part of the globe is agitated.

We feel every moment dreadful ſhocks; and in the plains of Riobomba the ſubterraneous noiſe reſembles that of a mountain falling to pieces beneath our feet.

The atmoſpheric air and the humid lands (all theſe volcanoes are in a decompoſed porphyry,) appear the great agents of theſe combuſtions, of theſe ſubterraneous fermentations.

Hitherto it was believed at Quito, that 2470 toiſes was the greateſt height where men could reſiſt the rarefaction of the air.

In the month of March 1802, we ſpent ſome days in the vaſt plains which ſurround the volcano of Antiſana at 2107 toiſes, where the cattle, when purſued, often vomit blood.

The 16th of March we diſcerned a path on the ſnow, a gentle ſlope, on which we mounted to the height of 2773 toiſes.

The air contained 0,008 of carbonic-acid, 0,218 of oxigen, and 0,774 of azote.

The thermometer of Reaumur was only at 15°; it was not in the leaſt cold, yet we bled at lips and eyes.

The ſite did not permit us to make an experiment with the compaſs of Borda, but in a grotto at 2467 toiſes.

The intenſity of in magnetic power was greater at that height than at Quito, in the ratio of 230 to 218. But it is not to be forgot, that often the number of oſcillations increaſes when the inclination diminiſhes, and that this intenſity is increaſed by the maſs of the mountain whoſe porphyries affect the magnetic needle.

In the expedition I made on the 23d of June 1802, to the Chimborazo, we have experienced that with patience one may ſupport a ſtill greater rarefaction of air.— We reached to a greater height than La Condamine (on the Corazon,) by 500 toiſes.

We carried inſtruments on the Chimborazo to 3031 toiſes; ſeeing the mercury deſcend in the barometer to 13 inches 11, 2 lines; the thermometer being 1° 3′ below zero.

We bled ſtill at our lips.

Our Indians forſook us as uſual.— Citizen Bonpland and M. Montufar, ſon of the Marquis of Selvalegre at Quito, were the only people who perſiſted: we all felt an uneaſineß, a debility, an inclination to vomit, which certainly proceeds from the defect of oxygen in theſe regions more than from the rarified air. I found only 0.20 of oxygen at this immenſe height.— A horrid fiſſure prevented us from reaching to the very ſummit of Chimborazo, from which we were only 206 toiſes.

You know that the height of this coloſſal maſs is ſtill uncertain.

La Condamine meaſured it from a great diſtance.

He allows it nearly 3220 toiſes.

Don George Juan gives it 3380.

This difference does not proceed from the various altitudes which theſe aſtronomers adopt for the ſignal of Carabouron. I meaſured in the plain of Taſſia a baſe of 1702 metres, (forgive me for ſpeaking ſometimes of toiſes and ſometimes of metres, according to the difference of the inſtruments I uſe:

you may be ſure that in publiſhing my operations I ſhall reduce the whole to the metre and to the centigrade thermometer).

Two geodeſical operations give me Chimborazo 3267 toiſes above the ſea: but the calculation muſt be rectified by the diſtance of the ſectant from the artificial horizon, and other circumſtances.

The volcano Tongouragoa has diminiſhed much ſince the time of La Condamine; inſtead of 2620 toiſes, I find it only 2531; and I hope this difference does not proceed from an error in my operations; ſince in my meaſures of Cayambo, Antiſana, Cotopaxi, and Illinga, I do not differ more than 10 or 15 toiſes from the reſult of La Condamine and Bouguer.— All the inhabitants of theſe miſerable countries ſay that Tongouragoa is perceptibly lower, while Cotopaxi, which has had ſo violent exploſions, is as high as in 1744, and even ſomewhat higher, unleſs that ariſe from an error on my ſide.

But the rocky ſummit of Cotopaxi ſhews that it is a chimney which reſiſts and preſerves its figure.

The operations we have made in the Andes of Quito, from January to July, brought the inhabitants the ſad news that the crater of Pichincha, which La Condamine ſaw full of ſnow, burns anew; and that Chimborazo, whom they thought ſo peaceable and harmleſs, has been a volcano, and perhaps one day will be ſo again.

We have burnt rock and pumiceſtone at the height of 3031 toiſes.

Woe to mankind if the volcanic-fire (for we may ſay that the flat of Quito has been one volcano with ſeveral tops,) breaks forth through the Chimborazo.

It has often been ſaid in print that this mountain is of granite; but there is not one atom of that.

It is here and there porphyry in columns, encruſtating vitrous field-ſpath, horn-ſtone, and olivin. The bed of porphyry is 1900 toiſes thick.

I might mention to you on this occaſion a polar porphyry, which, analogous to the ſerpentine I have deſcribed in the Journal de Phyſique, has poles without attraction: I might quote to you other facts relating to the great law of the ſtratas, and their enormous thickneſs near the equator: but it would be too much in a letter which may be loſt; and I will treat of that ſome other time.— I only add, that beſides the elephants’- teeth which we have ſent to Citizen Cuvier from the flats of Santa Fé, of 1350 toiſes in height, we keep for him others ſtill finer; ſome of a carnivorous-elephant, others of a ſpecies little different from that of Africa, from the valley of Timana, the town of Ibarra, and from Chili.

Thus, then, is the exiſtence of that carnivorous monſter certain from Ohio, in the 50th° north latitude to the 75th° ſouth latitude.

I have ſpent very agreeable hours at Quito.

The Preſident of the Audience, Baron de Corondeles, has loaded us with kindneſs; and for three years I have had no reaſon to complain for once of the Agents of the Spaniſh Government.— Every where I have been treated with diſtinction, and with a delicacy which obliges me to an everlaſting gratitude.

I have been very attentive to the pyramids and to their foundation, which I do not believe in the leaſt deranged as to the Pierres Molaires.

A generous individual, a friend of ſciences and of learned men, ſuch as La Condamine, Godin, and Bouguer—namely, the Marquis of Selvalegre, at Quito, thinks of rebuilding them—but this leads me too far.

After having paſſed the Aſſonay and Cuença, (where they gave a bull-baiting,) we took the route of Loxa, to complete our operations on the Chincona.

Afterwards we ſpent a month in the province of Jaen , of Bracomoros, and in the Pongos of the Amazone, whoſe banks are adorned with the Andira and Bougainvillea of Juſſieu.

Methinks it is important to fix the longitude of Tomependa and of Chuchanga, where begins the chart of La Condamine, and to connect theſe points with the coaſt.

La Condamine could only fix the longitude of the mouth of the river Napo: there were then no time-pieces; ſo that the longitude of theſe places ſtand in need of ſeveral corrections.

My chronometer of Louis Berthoud does wonders, as I am convinced by obſerving from time to time the firſt Satellite of Jupiter; and by comparing point for point the difference of my meridians from thoſe found at the expedition of M. Fidalga, who, by the King’s order, made trigonometrical obſervations from Cumana to Carthagena.

From the river Amazon we paſſed the Andes by the mines of Haalgayac, which produce a million of piaſtres yearly, and where the mine of grey argentiferous copper is found at 2065 toiſes.

We came down to Truxilla by Caſcamarca, (where, in the palace of Atatualpa, I have drawn the arches of the Peruvian vaults.

Continuing by the deſerts of the South Sea Coaſt to Lima, where one half of the year is covered with thick vapours, I made haſte to arrive at Lima, in order to obſerve the Tranſit of Mercury on the 9th Nov. 1802.

Our collections of plants, and the drawings I have made of the anatomy of the genera, agreeably to the ideas Citizen Juſſieu had imparted to me in the Society for Natural Hiſtory, have greatly increaſed the riches we have found in the province of Quito, at Loxa, at the Amazone, and in the Cordillieres of Peru.

We have found many plants ſeen by Joſeph Juſſieu, ſuch as the Llogue affinis quillajac, and others.

We have a new ſpecies of julienne, which is charming; collatix, paſſiflora, and loranthus, a tree ſixty feet high.

We are very rich in palms and gramina, on which Citizen Bonpland has laboured very extenſively.

We now have 3784 very complete deſcriptions in Latin, and nearly one third of the plants in the Herbarium, which, for want of time, we have not been able to deſcribe.

There is not a vegetable of which we cannot point out the rock it inhabits, and to what height in toiſes it mounts; ſo that the geography of plants will find in our manuſcripts very correct materials.

In order to do ſtill better, Citizen Bonpland and I have often deſcribed the ſame plant ſeparately.

But two thirds of the deſcriptions, and more, belong to the ſole aſſiduity of Citizen Bonpland, whoſe zeal for the progreſs of ſcience cannot be ſufficiently admired.

Juſſieu, Desfontaines, and Lamarck, have reared in him a diſciple who will go great lengths.

We have compared our herbarium with thoſe of M. Mutis; we have conſulted many books in the immenſe library of that great man: we are perſuaded that we have found ſeveral new genera and new ſpecies: but much time will be required to determine what is really new.— We mention alſo a ſilicious ſubſtance analogous to the tabaſchin of the Eaſt Indies, which M. Mutis has analyſed.

It is found in the knots of a gigantic gramen which is confounded with the bambou; but its flower differs from that of the bambuſa of Schreber. I know not whether Citizen Fourcroy has received the milk of the vegetable-cow, (as the Indians call the tree.)

It is a milk which, prepared with nitrous acid, produced a caoutchouc with a balsamic odour, but which, far from being cauſtic and hurtful, as all vegetable milks are, is nouriſhing and agreeable: we diſcovered it on the the road of Orenoque, in a plantation where the negroes drink often of it. I ſent alſo to Citizen Fourcroy by Guadaloupe, and to Sir Joſeph Banks, by the Trinidad, our dapiché; or the white oxygen caoutchouc, 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 Rio Negro.

At length, after waiting three years, La Mecanique Celeſte of Laplace is arrived, (November 1802;)

I have fallen upon it with unbounded eagernefs.

This book has encouraged me to continue my reſearches on the tides of the atmoſphere, on which I made ſeveral obſervations at Cumana in the year 1799. I have mentioned them in a letter to Citizen Lalande.— Godin knew ſomething about them, without pointing out a cauſe.

Moſely, in a work on the maladies of the Tropics, ſays, that the barometer is at the maximum when the ſun is in the meridian; but that is very falſe.

The maximum takes place at 21 h. and at 11 h.; the minimum at 4 h. and at 15 [Formel] h. The Moon does not ſeem to alter the epochs ſo much as the quantity of elevations.

I am now obſerving principally the days of oppoſition and conjunction; and as my barometer indicates the 20th part of a line, I doubt not but Citizen Laplace, whoſe genius has conquered the tides of the ſea, will alſo diſcover the laws of the tides of the air, when I ſhall have given him ſome thouſands of obſervations.

See how ſtriking the phenomenon is:

f. l.

24 November, 10 h. morn. 27 5 75 ——— ——— 12 49 m. 5 45 ——— ——— 2 0 5 25 ——— ——— 3 30 5 10 ———— —— 4 45 5 0 ———— —— 5 30 5 10 ——— ——— 7 0 5 40 ——— ——— 8 0 5 60 ——— ——— 9 0 5 65 ——— ——— 10 30 5 65

I obſerve the hygrometer and barometer at the ſame time.

My barometer is Engliſh.

I have gone too far.

I wiſhed to write my friend Pommard. I have no more time; he loves me, he will excuſe me.

I don’t go to the Philippines. I paſs by Acapulco, Mexico, Havannah, to Europe. I hope to embrace you in September or October 1803, at Paris.

I ſhall be at Mexico in February; in June at Havannah. I think of nothing but of preſerving and publiſhing my manuſcripts.— How much do I long to be at Paris!

Health and reſpect, Humboldt.