Liber Meteororum
A book of celestial appearances – an outline
translated by Anna Aly-Labana

When Paracelsus wrote his „Liber Meteororum“ in 1530, the newly invented printing press made it possible to disseminate published texts on a wide scale.

From 1500 on, the so called „Einjahrespraktiken“ (yearly almanacs) became popular among common people in German-speaking countries. These almanacs provided astrological forecasts by interpreting planetary constellations in relation to the weather, the harvest, epidemics and wars. Also very popular in the 16th century were books like the „Wetterbüchlein“ (weather booklet) or „Bauernpraktik“ (advice for farmers) that offered a set of rules regarding the weather and astral constellations and could be applied on a more long term basis.

Alas, for his Liber Meteororum, Paracelsus could not find a publisher. Like most of his texts, it too wasn`t published until some decades after his death. How is the lack of interest among his contemporaries to be explained?

For one, Paracelsus` Liber Meteororum can`t be applied practically to predict the weather. He even contends, that planetary constellations have no influence whatsoever on weather phenomena, thereby challenging a widely held supposition in those days.

The Liber Meteororum is a philosophical work about nature, in which Paracelsus presents his theory on the formation of weather phenomena in 81 pages. His text is structurally and compositionally oriented on the antique text “De Meteore” by Aristoteles, but he presents new explanations and does this, moreover, in German! His theory contradicted the generally accepted academic position and therefore appeared to be unpublishable at the time.

Like Aristoteles, Paracelsus deals with all appearances of the sky. This includes not only winds, precipitation, storms and rainbows, but also times of the day, seasons, falling stars, meteorites and a phenomena called frog rain, particular to Paracelsus.

In the Aristotelian cosmology the world is composed of horizontal layers of the four elements. Between the lowest element “earth” and the uppermost element “fire” are the elements “water” and “air”. The meteorological phenomena appear in the uppermost element “fire”. Paracelsus adopts this concept and elaborates it. To him, each element has its particular “fruit”; the “fruits” of the celestial fire element are the stars.

The stars are the central element in the Paracelsian vision and it is around them that everything revolves. Paracelsus developed a unique theory, which, (according to my knowledge) was never widely discussed: not the planetary constellations produce the weather, but the stars themselves. In the Liber Meteororum we encounter special “weather stars” of which each one begets and ”brews” a particular weather condition. Paracelsus thus speaks of “rain stars”, wind stars”, “lightening stars”, “hail stars”, “snow stars”, etc….
He describes in some detail how these stars “cook” the weather. It is here that we are introduced to the famous Paracelsian theory, which caused so much uproar after his death and was the subject of heated debates for centuries to come. As a physician Paracelsus attributed a great deal of importance to alchemy, for one in the production of medicine, but also in order to understand the human body and its ailments better. Based on the traditional Hellenistic- Arabian two-factor theory, according to which all metals are composed of mercury and sulphur, Paracelsus extended the theory by a third factor, that of salt (sal) and postulated that all material bodies, including the human, function through these three principles. These three principals are not actually grounded in the substances mercury, sulphur and salt themselves, but rather in properties that are associated with them. Although these principals encompass mental aspects, Paracelsus doesn`t, as it is often interpreted, mean body, soul and mind, but rather relates these “substances” as he sometimes denominates them, solely to the body.
Consequently, stars too are composed of these three substances and each star is made up of three individual variations of these principals. Through the reactions that take place among the substances,“ ire operationes“ as Paracelsus calls it, precipitation, winds, lightening and thunder are produced. In his very expressive descriptions of these reactions he borrows terms like “resolviren”, “dispensiren”, “coaguliren” from the alchemists` kitchen. The stars themselves are named after laboratory flasks “Hafen”, “Athanar”. Roughly categorised sulphur e.g., is associated with an inflammable principle, mercury with a motile one and salt with a solidifying principle. In the end there are no limits to the various possibilities of chemical reaction and the theory enables Paracelsus to describe every visible phenomenon.

Paracelsus describes not only meteorological phenomena in the sense of the word as we understand it today, but also climatic occurrences such as temperatures. He stresses, that it is not the position of the sun that is responsible for the temperature changes in the course of the seasons, but rather the “summer-“ and “winterstars”, which he subsumes under the heading “weatherstars”, the sun being the supreme “summerstar” and the moon being the supreme “winterstar”. Without their special “mitgehülfen” (assistants) though, they could not cause the seasons.
Day and night are also produced by special stars. According to Paracelsus, it is not only the disappearance of the sun that is responsible for the darkness of night, but rather a type of star that produces darkness when the moon isn`t shining. He argues that, without these darkness-producing-stars, the sunrays would have to reflect past the earth (beyond the earth`s perimeter) also at night.
In favour of his theory is, that although the position of the sun on the 21st of June is at its peak, the temperatures are not, because the air isn´t yet heated up. He couldn`t know that the sunrays are not visible as light cones in space.

Winds too can regionally arise from “particularischen” windstars; Paracelsus distinguishes supraregionally quite simply between east-, west-, north- and southwind. In his view the temperature and humidity of each wind are determined by its windstar and not through the climatic condition in which it arises. Ergo, the windstar makes the climate, not the other way around.
The Paracelsian idea is that the wind can penetrate the water of the seas and thereby cause waves and stormfloods. Likewise the wind can penetrate the pores of the earth and cause earthquakes. Paracelsus adopted this theory from medieval scholars. Tectonic plates were unknown in those days.

Some of Paracelsus` contemporaries seemed to already have known that rain is the result of condensated water, because Paracelsus himself denied it vehemently. According to his theory rainstars beget each raincloud anew, just as a peartree brings forth pears each year anew. He compares rainstars with flowering trees. The rainclouds are the flowers and the rain their fruits. The duration and intensity of the rain depend on the amount of clouds and on the momentary composition of the three substances sal, sulphur and mercury.

Paracelsus attributes precipitation like snow, hail and sleet to the “winterstars”, inherent in which is “the spirit of coagulation” that turns water into ice and also makes rock crystal grow. The winterstars bring about winter and, here too, each type of precipitation is caused by a special star. However, sometimes hail comes down in the summer, which is then brought about by hybrid stars, that are neither “summer-” nor “winterstars”, but rather like mules, which are “neither donkey nor horse”. At this point Paracelsus seems to become victim to the nearly endless possibilities of meteorological conditions. His theory throws him out of the curve, he gets lost in contradictions and at the end of the chapter he extricates himself from the matter by stating that it isn`t necessary for humans to know how hail and snow are created. God simply made them.

As a catholic, Paracelsus` philosophy of nature has god as its unconditional base. Right from the first chapters of his Liber Meteororum, god is described as the creator of the primal material made from salt, sulphur and mercury, from which he then draws the four elements. The subtlest and first of these being the fire element – the sky.

God here acts as alchemist. Through his “göttliche alchimsterei” (divine alchemy) day is separated from night and heat from cold. For more differentiated processes however, god implements a force called “vulcanus” . Vulcanus already existed in several medieval alchemical treatises and is not a Paracelsian invention. Paracelsus describes him as a worker, who tends nature and brings things into their final form, just as god doesn`t personally sew the dress, but leaves that work to the tailor. Paracelsus explicitly emphasizes that Vulcanus is neither a person nor a spirit.

Aside from this, there are other vital and rational beings at work, rooted in popular belief of the age, that have sprung from a pre-Christian mythology. Paracelsus speaks of nature spirits that populate all four elements. Unlike Vulcanus, who is indispensable at the locus of weather production, the elementary spirits play only a very marginal role. Elementary fire spirits are solely instrumental in directing lightening bolts, which, in accordance with the will of Christ, they can aim at god`s enemies.

The lightening bolt as the most powerful of the celestial apparitions, expounded verbosely and with great detail, is as usual in his philosophy of nature, the result of a reaction of the three principals within a lightening star. At the same time, the lightening bolt can be seen as a wink of god, reminding mankind to lead a pious life, because Christ heralds his return through a bolt of lightening.

At times the devil too has opportunity to cause storms and tempests, just as he can possess man and beasts. However, ultimately the devil only serves god “um die seinen (…) in das ewige feuer zu holen” (in order to bring his progeny into the eternal fire).

The final two chapters deal with extraordinary heavenly apparitions like rainbows and falling stars, sheet lightening and meteorites, as well as occurrences that lie beyond the experience of our current day and age, such as dragons, frog-, or stone rain. And even though Paracelsus retains his characteristic scholarly style, the three principles here no longer serve to explain these apparitions.

The elementary fire spirits, which he calls “Pennaten” are dealt with at great length. They produce the so called “praesagia”- omen that can assume various forms, foretelling the future and want to be interpreted by people. These can be rainbows, rings around the sun or moon, today known as lunar or solar coronas. Rocks or metal falling from the sky is also attributed to the Pennaten. Most peculiar are figures in the form of crosses, goats, cocks, sows or human heads, either cast down from or drawn as pictures in the sky by the Pennaten.

Paracelsus explains that phenomena like falling stars are not dependent on the Pennaten. He understands them to be an excrement of the stars, which feed the fire, prevalent in the sky. Sheet lightening too is an excrement of the stars and in particular one of the summer stars in the form of burning sulphur.

There are other beings aside from the Pennaten in the sky. E.g. dragons, fiery beings “schießen von einem berg zum anderen” (that shoot from one mountain to another). Afterwards they consume themselves and become aspic (jelly-like substance)!

Alongside these, certain frogs live in the sky element, that under particular weather conditions rain down from there. Incidentally, the sperm of tree frogs principally originates in the heavens and in the spring fall down from there. A phenomenon described by a contemporary as “bloodrain”, which most likely was sand from the sahara that comes down during a general climatic condition in the alpine region, was interpreted by Paracelsus as being rain dissolved in the “foam of dawn”.

Five years before he wrote the Liber Meteororum, Paracelsus published another work of natural philosophy. The “Philosophia generationibus quator elementorum” is a treatise on all products of the elements and thus also of the weather phenomena. Surprisingly, here we find a  different allocation of the weather stars. The air element has the outer position. The weather is still located in the fire element. God as alchemical protagonist finds just mention in the first book about the „air“. In the second book, according to the „fire“ he is not apppearing and neither do Vulcanus, nature spirits or the devil.
The explicit alchemical description of weather phenomena are also found in the Philosophia generationibus quator elementorum, focussing in particular on the interplay of the three principles, though the reaction of the substances in detail are portrayed differently. A “thunderstar” here is responsible for thunder, while in the Liber Meteorum it is only a byproduct of lightening. Furthermore, fog, frost and dew are described as “perspiration” of the stars.

How can these conceptual differences be explained? It is apparently not Paracelsus` intention to proclaim a static theory. His view of the world is associative and can therefore vary.

He employs what we today term `fantasy` and engages in `speculations`. Curiously, he rejects both of these paths vehemently as a means of attaining knowledge. In his opinion, a physician should not fantasize or speculate, but should base his experience on the “light of nature”.

Regarding his view on the weather, as we have seen, his method led him to the theory of the weather stars, within which three substances cook up the weather.
His description of the world is very religious, full of metaphors and wonder about the colourful multitude of appearances. At the same time he is absolutely driven to make the laws of nature explicable on the basis of all-pervasive chemical reactions – not very different from our understanding of the laws of nature.