The First Letter

Letter Summary: In this letter, Volta references previous communications that Father Campi and Volta have been sharing for an unknown period of time about a source of “Flammable Air” the Father is aware of. This “Flammable Air” will eventually be called methane. The Father’s source is a stream of bubbles rising from the bottom of a lake. They were supposed to meet again for an expedition to study the source, but the opportunity somehow fell apart. Volta felt bad, but he’d already become excited about the research and so began independent work to find his own source. He found not only one source, but many sources. Many rivers, lakes, and other bodies of water could be made to release methane bubbles if their muddy bottoms were vigoroulsy stirred. He found that you didn’t even need to be in the lake, as you could dig a hole in dry ground near the water, fill that hole with water, and watch the bubbles rise that were previously invisible. Volta was wondering if he could also get methane from manure and decaying vegetation when he got sick. When he got better, he investigated reeds along a lake shore and surprised his guests when he rummaged around the reeds, collected the bubbles in a vase, then lit the the air from the vase on fire. Interesting for the history of the rocket engine is that he discovers that making the jar’s neck too narrow leads to a series of small explosions, whereas a wider neck leads to a steady flame. He further finds that making the neck narrower than the vessel’s cavity and lowering a candle into it leads to even higher flames. (These could be considered rudimentary detonation engines when the neck is too narrow and rocket nozzle concepts when the ratio of inlet/throat/outlet areas are optimized for stronger flames. He further stumbles upon fuel/air mixture optimization, which he discusses in future letters.) He remarks how beautiful the azure flames are and closes out the letter.

Editor's Note: If you didn't read the overview, this translation is "best effort" from someone who doesn't know Italian, let alone Italian from the 1700's. Google and other websites choke on some of the words and prose, so I've taken some liberties to bridge gaps. If you speak Italian, I've presented my typed conversion from images of the letters at the bottom. Your improved interpretations will, of course, be greatly appreciated.

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To Father Carlo Giuseppe Campi

Written 14 November 1776 from Como, Italy

Dearest friend,

When you first wrote to me about the source of flammable air found by you at the beginning of autumn, and then we talked for a few days together, you will recall how many communications, and how many conjectures were made between us on the increasingly marvelous and interesting subject of the different species of air, and especially on that which you discovered nearby...

...of the beautiful Colle,
Whose Lambro is the foot,
And to which Colombano the name gave,
Where the vines in tangled lasciviousness
Are married in place of Olmi in 'Figs
- Redi Ditir

...and as we already prepared to go there in the company of another lover of Natural History to examine with ease and care the depths from which this air is transmitted, the water through which it gurgles, the surrounding land, and the slopes of those fertile, amiable Poggi. Perhaps with the object of conferring with me, you went to Como; I certainly went to Milan with you to join this expedition and studious research. How badly I felt when this beautiful opportunity vanished, I can not express: it was good, however, that the ideas then conceived of the research to be done in the surroundings of that place, initiated with me, with less expenditure, and little expected ease, a not inferior but rather a much better success. What will you say, if I reveal to you, that I have found and collected Flammable Air in other regions, where I happened to be in the current autumn, and even here at my house? Wherever I am, turn me to the right or to the left, I have very few steps to take before the earth and water provide me with beautiful and well-prepared flammable air, in whatever quantity I am like to want? So it is, my friend, the bubbling up through the water from the bottom the bursts of flammable air, which is an extremely curious phenomenon, as it seems to us to be rare or almost new, and opens the way for other important research, yet it is not, nor should it be considered again, as something unique to the source observed by you, since I have collected this air in very different sites, from lakes, from ponds, from reservoirs; and I also have found you do not want to only take into account a singular prerogative of spontaneous bubbling in large quantity and in long stretches, as does the air of your source, when I have found in other sources that it is better to initiate the gurgling with vigorous stirring of the bottom. I refer with pleasure to Verbano Lake, which offered me, before any other, the spectacle sought, yes, but not hoped for: and my Lario Region did not break from the newly conceived and founded expectation; some streams and some pools far exceeded it. 

Here's the method of how I made my discovery, Sovvengavi, as I would have proposed to you (if I were there with you, where you made the first find): make some excavations in the ground not far from the bubbling source and fill the holes with water to submerge the land and to imprison the rising air, if any, which comes to the surface in the form of bubbles. Together, we would have collected the gas in the usual way in jugs with their mouths immersed in the water and then examined whether this pure air was flammable or was of any other airs of the many made known to us for the first time. I had added to this method (as I was meditating its use for collecting air and investigating it) the idea of testing it on manure and other corrupt matter, when I fell ill. Now well again, and full of these ideas, I did not first look at muddy waters. Instead, I took a boat on Lake Maggiore skirting certain reeds near Angiera. On day three of this expedition, I began exploring the reeds with a stick when the air (of which I saw copiously surfacing) aroused in me the desire to collect a good dose in a capable glass jar. I would have believed it, as was a seemingly obvious thing, to be putrid air and phlogistic and a sign that it would extinguish the flame of a candle, if the smell did not indicate to me that it could well have been flammable air, a smell so well known to me and which, after my many experiments, I must know how to distinguish. I frankly predicted to the people who were then with me, and to others whom I invited the following morning (November 4th) that the air would go up in flames, a show that brought them not a little surprise and my great satisfaction. 

Coming now to the minute details: This air burns very slowly with a beautiful blue flame, not otherwise than the one you have found. Because it alights and the flame appears vaguely, it is better that the mouth of the jar is wide rather than narrow, because if it is overly narrow, when you present it a lit candle, some bangs are created and they are many and successive, but all very weak, and such that you can hardly discern them. For small experiments, I choose to use a cylindrical glass jar three to four inches high, one inch wide in all its cavity, except in the mouth, which has a diameter of about half an inch. Approaching it with a candle, it is a lovely thing to see the mouth covered with a little blue flame that moves slowly down the internal walls of the vase, almost touching them, to the bottom; but the spectacle is more beautiful and more curious when a burning candle stub is immersed in the vessel itself by means of a folded iron wire; because then the azure-colored flame comes out more extended and with some sort of filler. If the candle is lowered deeply, it is extinguished, while at the vessel’s mouth the air continues to burn and the flame front goes slowly advancing towards the bottom. The downward traveling flame, which originated at the extinguished candle, lights the candle up again at the first contact with a candle edge. Is this not precisely what happens to oil, to the spirit of wine and so on? A torch dipped in one of these fluids does not go out. When approached to the surface of these fluids, it sets fire to them so that they happily burn. What more beautiful proof than this to demonstrate that the same flammable air, not otherwise than any other flammable substance, cannot burn except in contact with the pure atmospheric air? 

Yours,
Alessandro Volta

Original Italian

Quando mi scriveste primamente della sorgenta d'aria infiammabile da voi ritrovata sul principio dell' autunno, e quindi conversammo alcuni giorni insieme, vi ricorderà quanti discorsi, e quante congetture si fecero tra noi sul soggetto sempre più maraviglioso ed interessante delle diverse specie d'aria, e paricolarmente su quella da voi scoperta vicino...

“del bel Colle,
Cui baeia il Lambro il piede,
Ed a cui Columbano il nome diede,
Ove le viti in lascivetti intrichi
Sposate sono in vece d’Olmi a’ Fichi”
- Redi Ditir

...e come già ci disponevamo a recarci colà in compagnia di qualche altro amatore della Storia Naturale per esaminare con agio e attentamente il fondo da cui viene tramandata cotest' aria, l'acqua attraverso alla quale essa gorgoglia, il terreno circonstante, e le falde di quegli ubertosi amenissimi Poggi. Forse ad oggetto di conferir meco, voi vi portaste a Como; io sicuramente per associarmi a cosiffatta spedizione e studiosa ricerca, venni con voi a Milano. Quanto me ne sapesse male tosto che intesi svanito il bel progetto, io non vel so esprimere: buon però, che le idee allora concepite delle ricerche da farsi ne'dintorni di quel luogo, mi partorirono, con minor dispendio, e facilità poco aspettata, un non inferiore anzi assai miglior successo. Che direte, s'io v'annunzio a prima giunta, che ho ritrovato e raccolto Aria Infiammabile in altre parti, ove ebbi a portarmi nel corrente autunno, e perfino quì a Casa mia? Che, ovunque io mi trovi, mi volga a destra o a sinistra, ho ben pochi passi a fare, perchè la terra e l'acqua mi forniscano aria infiammabile bella e preparata, e in quanta copia mi piaccia di volerne? Così è, Amico, lo svolgersi e salir su dal fondo attraverso all' acqua vivi gorgogli di aria infiammabile, avvegnachè sia un fenomeno estremamente curioso, in quanto ci sembra o raro, o quasi nuovo, e ci apre la via ad altre importanti ricerche, non è, nè debbe più riputarsi cosa propria della sorgente da voi osservata, da poi che io ho raccolto di tal' aria in diversissimi siti, da laghi, da stagni, da fonti; ove però non si voglia aver in conto di singolar prerogativa il gorgogliare spontaneamente, e in copia grande, e tratto tratto, come fa l'aria del vostro fonte, quando negli altri conviene per lo più eccitare il gorgoglio, con ismuovere e rimestare il fondo. Mi richiamo con compiacenza il Verbano, che mi offrì prima d'ogni altro lo spettacolo ricercato sì, ma non isperato: quindi il mio Lario non ismentì la concepita e fondata aspettazione; alcuni rigagnoli poi, e alcune pozze la superarono di gran lunga.

Ecco come m'avvenne di fare la scoperta Sovvengavi come io proposto vi aveva (se iti fossimo là, ove faceste voi il primo ritrovamento) di fare non lungi dalla sorgente alcuni scavamenti, e ricolmatili d'acqua sommouevere con checchessia la terra sottoposta per isprigionarne l'aria, se ve ne avea, la quale venuta a fior d'acqua in forma di gallozzole, avremmo raccolta al modo solito in caraffe immerse colla bocca nell' acqua, per indi esaminare se cotest' aria pure era infiammabile, o di alcun' altra delle tante fatte a nostri dì per la prima volta conosciute; vi soggiunsi eziandio come io andava meditando di usare cotal mezzo di raccoglier aria e spiarla, sopra il letame, ed altre corrotte materia, quando, ripatriato, ne avessi il comodo. Or bene, pieno di queste idee, non prima m'avvenni a guardare un' acqua limacciosa, e ciò fu nel diportarmi in una navicella sul Lago Maggiore, e nel costeggiare certi canneti vicini ad Angiera, il giorno 3 del corrente, che messomi a frugarvi dentro col bastone, l'aria cui vidi copiosamente portarsi a galla, mi destò la brama di raccoglierne una buona dose in un capace vaso di vetro. Io la avrei creduta, come era cosa ovvia, aria putrida, e flogisticata a segno di spegnere tostamente la fiamma di una candela, se l'odore non m'indicava, che potea ben essere aria infiammabile, odore a me tanto noto, e cui per molti esperimenti fatti debbo pur saper distinguere, che francamente predissi alle persone le quali allora eran meco, e ad altre che invitai la mattina seguente, 4 Novembre, che quell' aria sarebbe andata in fiamma, spettacolo che s' avvero con loro non poca sorpresa, e mia molta soddisfazione.

Venendo ora alle minute circostanze. Quest' aria arde assai lentamente con una bella vampa azzurrina, non altrimenti che quella da voi ritrovata. Perchè si allumi, e ne apparisca in vago modo la fiamma, conviene che la bocca del vaso sia larga anzi che no, perchè se è soverchiamente angusta, al presentarle una candelleta accesa, nascono bensì degli scoppietti e molti e successivi, ma tutti debolissimi, e tali che appena potete discernerli. Io soglio adoperare, per le esperienze piccole, un vasello di vetro cilindrico alto dai tre ai quattro pollici, largo uno in tutta la sua cavità, salvo che nella bocca, la quale ha intorno a un mezzo pollice di diametro. Appressandovi una candela, è pur cosa graziosa il vedere coprirsi la bocca d'una fiammetta azzurra, e questa giù scendere lento lento lunghesso le pareti del vaso, quasi lambendole, fino al fondo; ma più bello e più curioso riesce lo spettacolo, ove s'immerga nel vasello medesimo, per mezzo di un filo di ferro repiegato, un mozzo di candeletta accesa; perchè allora la fiamma di color cilestro esce più stesa e con qualche sorta d' empito. Se la candela vien calata profondamente, s'estingue, mentre sulla bocca l'aria arde tuttavia, e va pian piano avanzandosi verso il fondo, da cui discostando la candela si riaccende al primo toccar la fiamma che avvampa su l'orlo. Cio non e appunto quello stesso che accade all olio, allo spirito di vino ec.? Una fiaccola tuffata in uno di cosiffatti fluidi non si spegne, che accostata alla superficie vi appicca fuoco cosicchè allegramente ardano? Qual più bella prova di questa per dimostrare che la stess' aria inflammabile, non altrimenti che qualunque altra sostanza accensibile, non può ardere se non in contatto dell' aria pura atmosferica? Sono ec.