Spectrum of elements and ethers

The 'lower' elements and 'higher' ethers are the result of the previous evolutionary stages and arose through sacrifice of high spiritual beings that gave the substance for other lower spiritual beings to grow and develop. Our physical reality is made up from, or woven from these elements and ethers, though each of them represents a class of spiritual beings in itself.

In each planetary stage, an element-ether pair was created: two kinds of warmth on Old Saturn, air-light on Old Sun, water-chemical ether on Old Moon, and earth-life ether on Earth. See the Four elements

Each of these elements and ethers has its own set of laws, see the section about the formative forces for an example of how different these are from what is described as physical laws.

The four elements were known by all ancient religions and teachings from India, Egypt upto the Greek culture, can still be found in esoteric teachings in the middle ages, as well up to today in Alchemy or hermetics.

Elements and ethers are concepts mapping to the influences of spiritual beings such as Elementals of nature and the elementary kingdoms, they can be regarded as a sort of macroscopic label or shorthand to denote their distinct influences, in order to have a 'language' to describe what is underlying the the kingdoms of nature.

At the end of the 19th century, theosophy re-introduced the ancient indian term of the tattvas as the formative forces underlying the four elements (a.o. Rama Prasad), whilst contemporary scientists were exploring the vibrations of the so-called 'ether' as a theory of physics to understand matter (a.o. Oliver Lodge, Gustave Le Bon). More on this paradigm below under 'Aspects' for 'the ether', and on the topic page formative forces for 'tattvas'.

Aspects

• the cosmic ether consists of two parts: a) warmth, light , chemical, and life ethers b) a moral being of the cosmic ether present near the stars and planets. Man thus lives within the cosmic ether as moral essence (1922-11-12-GA266/3)
• the spectrum of elements and ethers is differentiated between the Earth and the Sun (1910-08-23-GA122)
  • On Earth we have the elements up as far as warmth which permeates the Earth. In the Earth we have to look for the solid, fluid and gaseous elements; warmth is shared by both Earth and sun.
    • Light streams upon the Earth from the sun. The Earth only shares in light in so far as the beings in its environment (or the bodies in its environment) take part in the life of the Earth.
    • If we wish to locate the higher elementary states (light ether, chemical ether, and lifeether) we must place them in the sphere of the sun.
• for the principle of differentiation
  • see Old Saturn for the example explanation of differentiation of inner warmth and outer warmth by the Archai
  • note - the spectrum of ethers and elements has to be overlaid by the evolutionary pattern of the different planetary stages of evolution creating the different planes or worlds of consciousness - see also Schema FMC00.143 on The elementary kingdoms
• for an explanation on warmth, see Schiller (downloadeable in Further reading section below)
• the life ether was called Honover in Persian times, in the Gospel of John it's called the Logos (as the 'meaning-filled tone belonging to the Being of the Sun') (1910-09-12-GA123)
• evolutionary, the separation of the Sun with the Earth also implied a separation of the influences of the higher ethers that working on Man from the Earth before, and now from outside after. This changed again after the Mystery of Golgotha, and relates to the Christ Impulse on Earth, see Christ Module 11 - A new physics
• ethers and geometrical forms of the corresponding formative forces or tattvas: sphere, triangle, rectangle and crescent moon; and the fifth (akasha or thought ether: two intersection spirals) (1906-12-01-GA266) - see formative forces

Ether

• the concept of the ether was explored by renowed physicists at the end of the 19th century, as a way to explain nature and the duality between matter and wave phenomena. The idea was that all phenomena were the result of vibrations of 'the ether' at different levels, the most well known being light.
  • This hypothesis still makes sense, however one needs to position this into the 19th century which was extremely materialistic, and when natural sciences was investigating the nature of matter and phenomena such as light and radiation, the ether was imagined - erroneously - as very fine substance, just more fine than regular physical matter. Regarding the idea of a vibrating either, spiritual scientific sources such as Blavatsky, Harrison, Steiner referenced reputed scientists such as Oliver Lodge in this context. However this scientific idea of an ether did further evolve in the development of science, as it was overhauled by the stream of mathematical physics (relativity by Einstein, quantum physics by Schrodinger and De Broglie).
  • contemporary materialistic 'mineral science' considers the electromagnetic spectrum whereby the visible light is a small section of a spectrum ranging from high energy gamma rays and X-rays, over UV-visible-IR, to lower frequency/energy long microwaves and radio waves. As physics only considers the mineral element Earth, it views everything as electromagnetic waves. An alternate view is to consider that there is an ether vibrating at a wide range of frequencies, as a spiritual wave that is loosing energy and crashing into matter. The logical mind can imagine a cosmic breath exhaling from high energy (gamma rays, X-rays) over light to low energy.
• Rudolf Steiner taught about the various ethers, spiritual beings underlying these formative forces (see the Elementary Kingdoms), and presented how the whole could be viewed in a framework as explained on Force substance representation

Inspirational quotes

1909-04-12-GA110

Nothing one-sided comes forth in the world. Everything that exists has two sides to it.

.. a transmutation, a bewitching of spiritual being is always connected with these processes of condensation and with the formation of gases and solids

.. look around at our world: we see solid rocks, flowing streams of water, we see water changing into rising mist: we see the air, we see all the solid, liquid, gaseous things and we see fire, so that at the foundation of all things we have nothing but warmth. All is warmth or fire — solidified fire .. all things were once upon a time warmth or fire; everything has been born out of fire.

Illustrations

Schema FMC00.084 gives an overview of the four elements and four ethers (there are two sorts of warmth hence the overlap).

Schema FMC00.172 elaborates on the simpler FMC00.172A (see: Force substance representation). It shows how on physical Earth, coarse substance is 'Matter', and fine substance becomes 'Force', in the language of physics in mineral science. However between coarse substance (atoms) is the fine substance (ethers, force), and both form a balance that sustains itself, a bit like an extension of the phase diagram in chemistry.

Schema FMC00.078 is added to read the left column of FMC00.084 (above) above with the symmetry in FMC00.006 (below), more info on the relationships represented by the colours in Planes or Worlds of Consciousness

Schema FMC00.194 shows how during the preceding planetary stages (and recapitulations on Earth), the elements and ethers were created, in a way that the spiritual hierarchies all remain present in the totality of the whole spectrum of elements and ethers.

Schema FMC00.225 is a summary of the GA132 lectures that sketch - in imaginative pictures - the spiritual principles underlying the appearance of the elements and ethers. These principles (sacrifice, bestowal, renunciation .. ) and imaginations provide deeper meaning and understanding of the 'philosophical principles' of the elements and ethers, i.e. the working of the spiritual hierarchies.

Schema FMC00.006A sketches the formation of the four elements in the physical domain and the current Condition of Form as a result of the third recapitulation, with its origin in previous evolutionary stages. See eg 1908-03-16-GA102. The schema FMC00.006 embedded in the lower right shows how a substance can appear in multiple 'form appearances', see also Potentization

Schema FMC00.149: gives a tabular synthesis showing the development of the Spectrum of elements and ethers and the development of our current Four kingdoms of nature as well as Man's developing Condition of Consciousness, see also Schema FMC00.583 on Man and nature's kingdoms in evolution

It shows how the plant and animal kingdoms evolved from the planetary stages of evolution: part of the development lagged behind and was not able to develop the next structural bodily principles, such as the astral on Old Moon, and the human 'I' on Earth.

Note: this schema has a Schema Commentary page, right click the schema number hyperlink to open in a new tab window.

Schema FMC00.572 is a sampler with a selection of introductory books to get started on the study of the elements and ethers and formative forces.

Upper row, from left, the theosophical book by Rama Prasad referenced by Rudolf Steiner, then two books by Gunther Wachsmuth (not undebated), three booklets by Ernst Marti and one by Iwer Thor Lorenzen. Lorenzen book has been translated in English by the FMC project.

Second row from left, foundational books by George Adams and Olive Whicher, on projective geometry, as applied the study of the plant kingdom, then building on that, the exciting work that by Lawrence Lawrence Edwards and Nick Thomas.

Note: this overview was uploaded at the very start of this FMC wiki on 15-Mar-2020 but as it had a separate filename, it has now been put into a Schema for consistency on the site.

Schema FMC00.306 is a meta schema sketches that brings together a number of perspectives in a mind map, for contemplation and in support of didactic discussions.

On the left: FMC00.149 shows a simple table for the solar system evolution in the context of the cosmic fractal, an ever evolving simultaneous evolution of the different spiritual hierarchies along the main three dimensions of evolution. Below FMC00.147 shows the key relations between the hierarchies and Man and the other kingdoms, and the elements and ethers. Above FMC00.194 shows the principle of how the principle of sacrifice of a higher hierarchy (see also FMC00.077 not shown here) gives rise to an enrichment of the solar system cosmos as new substance and forces arise: the hierarchies remain at work in these, so they are embedded all the way as further developments unfold. Middle right FMC00.084 shows an overview of the spectrum of elements and ethers used as shorthand labels for this underlying spiritual reality, as a language for contemporary spiritual science (just as the language of alchemy was used in the middle ages). Right FMC00.172 depicts how to understand the spectrum in the context of the force substance representation, and this can be contemplated along FMC00.194 to retain the link to spiritual hierarchies. Below FMC00.005 looks at how these ethers and elements are at work in Man, but with a relation to the etheric spheres (FMC00.003 not shown here).

Schema FMC00.306 is a simple diagram by Ernst Marti (see 'Further reading' section below) to illustrate the point that, just as the physical is made up of a spiritual form filled with substance (compare for example the Cleansed phantom and Model for hereditary physical body with Human physical body), also the etheric is not just the formative force but also includes a process component as is obvious from the process of potentization used in homeopathy. This explanation is relevant in developing an understanding of the etheric formative forces in Man (eg Human etheric body and The double) and the kingdoms of nature.

To put this in context, compare with ao

• Schema FMC00.175 on The Elementary Kingdoms that shows how the formative forces are the 'form-giving' forces for minerals, plants, animals but need to be combined with the consciousness of the group souls)
• Schema FMC00.142 and variants on Overview Golden Chain and descriptions of the orchestration process by the third hierarchy H3 of the elementals of nature, see for example the description Rhythm of a year#1916-04-13-GA167

Lecture coverage and references

Coverage overview

Rudolf Steiner covered the warmth and light ethers in the first two scientific courses:

• 1919-12-GA320 light course (10 lectures) as well as 1903-08-GA091 (7 lectures on Light and colour)
• 1920-03-GA321 warmth course (14 lectures, but see also e.g. P.E. Schiller under references below)

Besides those two courses, an overall grasp can only be developed from the multitude of scattered lectures, as well as aspects covered in the third scientific course

• 1921-01-GA323 astronomy course (18 lectures)

Source extracts

Jakob Boehme

(1575-1624) had the concept of a 'dark ternary' and a 'light ternary' divided by a fourth property of fire or lightning (3 + 1 + 3 = 7).

William Law

(1686-1761) wrote 'The way to divine knowledge' (1752) to assist contemporary readers to a better understanding of Boehme's works. In the third dialogue the concept of the seven properties of nature is explained as (source: wikipedia)

.. the dark ternary of attraction, resistance and whirling became the ground of the “threefold materiality of earth, water and air (“an anguishing materiality”) out of which came the fourth property of nature as a “globe of fire and light” as the “true outbirth of the eternal fire”. Since this eternal fire is not a “moveable thing” and stands forever “in the midst of the seven properties” so the sun as the “true outburst of the eternal fire” is not a moveable thing and is therefore the centre and heart of the whole system, forever separating the first three properties from the three that follow, and thus changing the “three first forms of material wrath into the three last properties of the Kingdom of Heaven” .. the sun is the place that gives forth fire and light “till all material nature is dissolved”

Sir Oliver Lodge

It is the ether that gives place, through diverse modifications of its equilibrium, to all phenomena of the universe, from the impalpable light to the formidable masses of the worlds.

1906-12-01-GA266

We're always surrounded by five ether streams in the world around us on Earth. They're called earth, water, fire, air and thought ethers. ....

The cross sections of the five etheric streams and their connections with color, taste, and body regions are as follows:

• earth ether, square with only the corners distinct, yellow, sweet, bones and muscles;
• water ether, crescent moon at fifth day, white, tart, digestion;
• fire ether, equilateral triangle, red, hot, blood;
• air ether, circle, green, sour, nerves;
• thought (akasha) ether, two intersecting spirals — one is distinct, dark blue, bitter, lymph vessel system.

1907-10-xx-GA284

explains (p98-101) Johann Baptist van Helmont and his coining of the term 'gas' in his 'Ortus Medicinae'

"Hunc spiritum, incognitum hactenus, novo nomine gas voco" which means "Such spirit, which was not known until now, I will call gas"

That is the first time that this word appeared in this type of study or treatise.

This sentence teaches us quite a lot ... he had the feeling that we must address this transpararent substance as spirit ..

[continuation, also linking it to the term chaos, achaos, akasha]

1909-04-12-GA110

The ancient teachers may have spoken thus: ‘Look at that burning object. See how the fire destroys it. Thou seest two things in that burning object.’

In those ancient times one was called smoke, and it may still be so called nowadays, and the other was called light, and the spiritual scientist saw the fire in the middle between light and smoke. The teacher said: ‘Out of the flame are born simultaneously light on the one side, smoke on the other.’

Now we must for once put very clearly before us a very simple but very far-reaching fact, which has to do with the light, which is born of fire. It is most probable that many people when asked whether they see the light would answer: ‘Yes, of course.’ And yet this answer is as false as possible; for, in truth, no physical eye can see light. Through light one sees objects which are solid, liquid, or gaseous, but the light itself one does not see. Imagine the whole of universal space illuminated by a light the source of which was somewhere behind you, where you could not see it and you were to look into the world spaces illuminated through and through by that light. Would you see the light? You would see absolutely nothing. You would first see something when some object was placed within that illuminated space. One does not see the light, one sees the solid, the watery, the gaseous, by means of the light. One does not see physical light with the physical eye. This is something which comes before the spiritual eye with particular clearness. Spiritual science says therefore: light makes everything visible, but is itself invisible.

This sentence is important: light is imperceptible. It cannot be perceived by the outer senses: one call perceive what is solid, liquid, or gaseous, finally one can perceive warmth or fire outwardly. This one can also begin to feel inwardly, but light itself one can no longer perceive outwardly. If you believe that when you see the sun you see light you are mistaken: you see a flaming body, a burning substance out of which the light streams. It could be proved to you that you have there gaseous, liquid, and earthy substances. You do not see light, you see that which is burning.

But spiritual science says we pass in ascending order from earth to water, from air to fire, and then to light, we pass thus from the outwardly recognisable world, from the visible world into the invisible, into the etheric-spiritual world. Fire stands on the border between the outwardly visible, material world, and that which is etheric and spiritual, which is no more outwardly visible or recognisable.

What happens to a body that is destroyed through fire? What happens when something burns?

When something burns, we see on one side light appear, which is outwardly imperceptible and which is operative in the spiritual world. Something that is not merely outer material gives forth the warmth and when it is strong enough to become a source of light it yields something invisible, something which cannot be recognised any more through the outer senses, but it must pay for this in smoke. From what was formerly translucent and transparent it has to bring forth something not transparent — something of the nature of smoke.

Thus you see how warmth or fire becomes differentiated, how it divides.

• On one side it divides itself into light, with which it opens a way into the super-sensible world,
• and in payment for that which it sends up as light into the super-sensible world, it must send something down into the material world, into the world of non-transparent, visible things.

Nothing one-sided comes forth in the world. Everything that exists has two sides to it. When light is produced through warmth, then turbid, dark matter appears on the other side. That is the teaching of primeval spiritual science.

But the process we have just described is only the outer side, the physical, material process. At the foundation of this physically material process there lies something essentially different.

When you have only warmth in some object which as yet does not shine, then this warmth which you perceive is itself the outer physical part but within it is something spiritual. When this warmth grows so strong that it begins to shine and smoke is formed, then some of the spirit which was in the warmth must go into the smoke. That spiritual part which was in the warmth and has passed into the smoke, which being gaseous and belonging to air is a lower element than warmth, that spiritual part is transmuted, bewitched, as it were, into smoke.

Thus with everything which like a turbid extract or a materialisation is deposited by the warmth, there is also associated what might be called the bewitching of some spiritual being.

We can explain it still more simply. Let us imagine that we reduce air to a watery condition. Air itself is nothing but solidified warmth, densified warmth in which smoke has been formed. The spiritual part which really wanted to be in the fire has been bewitched into smoke. Spiritual beings, which are also called elementals, are bewitched in all air, and will even be bewitched, banished, so to speak, to a lower existence, when air is changed into water. Hence spiritual science sees in everything that is outwardly perceptible something that has proceeded from an original condition of fire or warmth and which has turned into air, smoke, or gas, when the warmth began to condense into gas, gas into liquid, liquid into solid. ‘Look backwards,’ says the spiritual scientist, look at any solid substance. That solidity was once liquid, it is only in the course of evolution that it has become solid and the liquid was once upon a time gaseous and the gaseous formed itself as smoke, out of the fire.

But a transmutation, a bewitching of spiritual being is always connected with these processes of condensation and with the formation of gases and solids.

Let us now look around at our world: we see solid rocks, flowing streams of water, we see the water changing into rising mist: we see the air, we see all the solid, liquid, gaseous things and we see fire, so that at the foundation of all things we have nothing but fire. All is fire — solidified fire: gold, silver, copper, are solidified fire. All things were once upon a time fire; everything has been born out of fire. But in all that solidified realm, some bewitched spirits are dwelling.

How are those spiritual, divine beings who surround us able to produce solid matter as it is on our planet — to produce liquids, and air substances?

They send down their elemental spirits, those which live in the fire: they imprison them in air, in water and in earth. These are the emissaries, the elemental emissaries of the spiritual, creative, building beings. The elemental spirits first enter into fire. In fire they still feel comfortable — if we care to express it by images — and then they are condemned to a life of bewitchment. We can say looking around us: ‘These beings, whom we have to thank for all the things that surround us, had to come down out of the fire-element; they are bewitched in those things.’

Can we as men do anything to help those elemental spirits? This is the great question which was put by the Holy Rishis. Can we do anything to release, to redeem, all that is here, bewitched?

1910-08-23-GA122

We have seen that the characteristic features of the Old Moon evolution were only able to come about through the separation of the Sun from the Moon. Then we have seen that during the Earth evolution it again became necessary for the sun to separate off from the Earth; we have seen that a duality is necessary for a life of full consciousness. The Earth element had to withdraw. But in such a withdrawal something else is also involved; the elementary conditions of the moon nature and of the sun nature change, become different. If you make a study of our present sun, even from a purely physical aspect you are obliged to say to yourselves: “The conditions which we have on Earth and which we call solid and liquid are not to be found in the physical sun.” The most you can say is that the sun still condenses to the gaseous state. This is recognised by modern physics. Such a separation of elementary conditions comes about through the severing of what was previously a unity.

We have seen that the Earth develops in such a way that a gradual densification downward takes place from warmth to solid, to earth, and that what is above as elementary existence light-ether, sound-ether, life-ether — seems to press inwards from without. But this description does not fit the part which goes out as the sun. It would be better therefore to say that there are seven states of elementary existence.

The first, the most rarefied state, which constitutes and brings about life; then what we call number, or sound-ether; then light-ether; then warmth-ether; then we have air, or the gaseous element, the watery element and finally the earthy or solid.

• It is in the earth that we have to look mainly for the elements up as far as warmth. Warmth permeates the earth, whereas the earth only shares in light in so far as the beings in its environment — or if you like the bodies in its environment — take part in the life of the earth. Light streams upon the Earth from the sun.
• If we wish to locate the three higher elementary states — light-ether, the ether of spiritual sound, and life-ether — we must place them in the sphere of the sun.

In the Earth we have to look for the solid, fluid and gaseous elements; warmth is shared by both Earth and sun.

1921-06-24-GA205 and 1921-06-26-GA205

In these lectures .. Rudolf Steiner describes four types of Earthly and Cosmic Laws, and takes the perspective as if an ancient Greek would converse with a contemporary scientist. The Greek would point out that all our current knowledge is just one type of knowledge or lawfullness, denoted with the element 'earth'.. Similarly, the second lawfullness, denoted with the element 'water', describes the etheric and its formative forces, not only in the plant kingdom but also in the inner movements or streams in the human being (forming the organs).

1921-04-12-GA313

(SWCC), see also The two etheric streams

.. the human being is thoroughly organized and inwardly organized with respect to water, to air, and to warmth. He is also differentiated with regard to the ethers, but this differentiation is a fluctuating one. It is a continual occurrence, a continual interplay between

• light and warmth ethers on the one hand, pressing centripetally from above downward, and
• life and chemical ethers on the other hand, pressing centrifugally from below upward.

By this means the etheric configuration of the human being is formed. It is actually a transformation of the vortex formed by the mutual impact of these two kinds of ether. The shape that you encounter must be understood then, as a cooperation between these two kinds of ether.

1922-11-12-GA266/3

The cosmic ether out of which our etheric body is taken, has two parts:

• The one part of this cosmic ether is made up of warmth ether, light ether, chemical ether, and life ether.
• Underlying all of this, as the second part, is a moral being of the cosmic ether. This moral being is, however, present only near the stars and planets.

Thus, when you live on Earth, although you do not know it during the day, you are also within the cosmic ether as moral essence (thus in both parts). However, the moral is driven out from between the stars by the sunlight. The sunlight itself has within itself nothing less than the original source of the moral ether for us. Yet, whoile the Sun shines it drives, through its light, the moral essence out of the ether.

...

[Ahrimanic influence]

When we go out of the physical and etheric bodies we leave begind the religious and the moral. And because the moral cosmic order is gone from the ether, the ahrimanic being has access to this ether. This liar-spirit speaks to human beings during their sleep and represents good as evil and evil as good.

Colours of the etheric

In 'Rudolf Steiner - Recollections by some of his pupils', F.W. Zeylmans talks about his first meeting with Rudolf Steiner and how he presented his findings regarding colours and sat there spellbound as he couldn't believe that anyone could give the answers to questions he could not even formulate properly.

The spectrum with the seven colours is only one part of the whole spectrum, the part that is visible in the solar system. To understand the whole spectrum one must draw a circle, and then there ar ethe sveen colours of the solar spectrum and on the other side the five peach-blossom colours. You ought really to have taken your start from these twelve. One sees these seven colours because there the astral body swims, as it were, in the colours. But the peach-blossom colour is so subtle and ethereal that it hardly appears at all in external nature; there the 'I' is living in the etheric; peach-blossom is actually the colour of the etheric.

Discussion

Note there is a difference between the ethers, and the (etheric) formative forces. This was the subject of a long standing 'dispute' between Gunther Wachsmuth and Ernst Marti, supported by ao Iwer Thor Lorenzen. Reference to Lorenzen's book on the subject.

However see Schema FMC00.172 and Schema FMC00.172A to resolve the dichotomy.

The reference by Law (and Boehme) describes the spectrum with warmth in the middle as the source of the other elements and ethers.

Related pages

• Force substance representation
• Four elements
• Formative forces
• Three mothers
• The two etheric streams
• Elementary kingdoms
• Three dimensions of evolution

References and further reading

• Rama Prasad: ‘Nature’s finer forces’ (1889).
• Gunther Wachsmuth (1893-1963)
  • The Etheric Formative Forces in Cosmos, Earth and Man: A Path of Investigation into the World of the Living - Volume 1 (1923 in DE, 1932 in EN)
  • The Ethereal World in Science, Art and Religion. From the Way of Man to Control the Image Forces - Volume 2 (1927 in DE, EN translation available by FMC project but not published yet)
• Hermann von Baravalle (1898-1973)
  • Wärme und Kälte , Magnetismus und Elektrizität (1940)
• Paul Eugen Schiller
  • Vom Wesen der Wärme (1961) - digital PDF version
• Iwer Thor Lorenzen (1895-1976)
  • Elemente, Aether und Aetherleiber - im Lichte der von Rudolf Steiner begründeten Geisteswissenschaft (typoscript 1976, original published in DE in 2016, EN translation available by FMC project but not published yet)
• Ernst Marti (1903-1985)
  • The four ethers: Contributions to Rudolf Steiner's science of the ethers, elements-ethers-formative forces (1974 in DE, 1984 in EN, also in NL)
  • The Etheric: Broadening Science through Anthroposophy - Volume 1: The World of the Ethers (1989 in DE, 2017 in EN)
  • The Etheric: Broadening Science through Anthroposophy – Volume 2: The World of Formative Forces (2020 in EN)

On the ether

• Oliver Lodge (1851-1940)
  • The Ether of Space (1909)
  • Ether and Reality: A Series of Discourses on the Many Functions of the Ether of Space (1925)

• Gustave Le Bon (1841-1931)
  • 'The Evolution of Matter' (1907, original in FR 1905 as 'L'Évolution de la Matière') - see online here, Chapters 3 and 5
  • La Naissance et l'évanouissement de la matière (1907) - not translated to date, but see 'The birth and disappearance of matter',see online youtube here
  • 'The Evolution of Forces '(1908, original in FR 1907 as 'L'Évolution des Forces')