The two available English translations of Gilbert's 'De
Magnete' are poor science translations of a somewhat poorly written work - but below are key extracts
from the Mottelay translation and more
here. Machine translations, such as offered
for convenience on this site, also give poor science translation.
Lancaster University UK does have a good online translatable version of the full original Latin 1600
We hopefully await an English translation by Dr Stephen Pumfrey and Dr Ian Stewart of Gilbert's other posthumously published 1651 Latin work "De Mundo Nostro Sublunari Philosophia Nova" (A New Sublunar World Philosophy, or A New Theory of Everything Under the Moon, or A New TOE) with Gilbert's apparently intended title "Physiologiae Nova Contra Aristotelem" (A New Science Against Aristotle). To quote Steve Pumfrey, Lancaster University science historian, "Gilbert's uniqueness in both natural philosophy and cosmology stems from his conviction that he had empirical proof of his theory of active matter." in 'Cambridge Scientific Minds' CUP 2002. (their still keenly awaited translation was initially planned for 2005)
From 'De Magnete' Book 1, Chapter III :
"But inasmuch as the spherical form, which, too, is the most perfect, agrees best with the earth, which is a globe, and also is the form best suited for experimental uses, therefore we purpose to give our principal demonstrations with the aid of a globe-shaped loadstone, as being the best and the most fitting. Take then a strong loadstone, solid, of convenient size, uniform, hard, without flaw; on a lathe, such as is used in turning crystals and some precious stones, or on any like instrument (as the nature and toughness of the stone may require, for often it is worked only with difficulty), give the loadstone the form of a ball. The stone thus prepared is a true homogenous off-spring of the earth and is of the same shape, having got from art the orbicular form that nature in the beginning gave to the earth, the common mother; and it is a natural little body endowed with a multitude of properties whereby many abstruse and unheeded truths of philosophy, hid in deplorable darkness, may be more readily brought to the knowledge of mankind. To this round stone we give the name microge, or Terrella (earthkin, little earth)."
"The terrella sends its force abroad in all directions, according to its energy and its quality. But whenever iron or other magnetic body of suitable size happens within its sphere of influence it is attracted; yet the nearer it is to the loadstone the greater the force with which it is borne toward it."
Of course Gilbert does discuss his theory ideas in various parts of his works often using different terms capable of different interpretation and translation - physics did not yet have an accepted technical jargon then, so that eg Gilbert himself had to invent some terms like 'electricity'. In another bit of latin innovation, he coined a term for mutually-attracting bodies coming together as 'coition' instead of 'attraction' - but, unlike his new 'electricity', that term did not catch-on in physics.
The latin term 'effluvia', meaning approximately 'emissions', was used by many before and after Gilbert but often in quite different and in some cases very unscientific theories. Hence atomists used 'effluvia' as proposed emissions of particles said to push bodies about - including an early theory of magnetism in which magnetic particle effluvia from magnets were supposed to push away the air between a magnet and a piece of iron so that the resulting vacuum sucked iron to magnets. Descartes' physics also involved such particle effluvia, and gasses and smells were also often called effluvia. Others have used 'effluvia' with a different sense, as either emissions of energy or of 'soul' or 'spirit' that left one body and if entering another body energised, enlivened or motivated it.
In all of these uses, the proposed 'effluvia' directly caused actions in bodies. Gilbert's physics theory was quite different in involving a variety of effluvia some of which he reasoned were probably particles and some not - and his effluvia signal emissions did not directly cause any actions but acted as signals to bodies receiving them and bodies themselves responded automatically as information response robots. Later such gravity signals were called 'emitted spirits' by Newton and Gilbert maybe should have invented a new term for his effluvia signals, but a term that covered a thing being both an automatic emission and acting as a received automatic signal did not exist then (and in English now might be something more like 'natural emission signals' ?) - making the understanding and translating of Gilbert physics with its robot-matter difficult. He is clear about the working of his magnetic effluvia and electric effluvia but is less clear about gravity and somewhat confusingly also uses the term effluvia for gasses with no such action. Uniquely his physics theory's ultimate atomic particles are basically nanorobots as the basis of all physics - including electricity, magnetism and gravity.
NOTE. Gilbert's effluvia signal emission explains gravitational and electric charge attraction decreasing as the square of the distance from a body, as his effluvia signal emissions spread and dilute evenly and the surface of spheres increases as the square of their radius. Inverse square force necessarily follows from any theory involving emissions of particles or of waves, excepting possibly when travelling through a medium ( eg gas, liquid or solid ) when losses might be expected to involve actual attenuation being somewhat greater than the square of the distance. Hence such forces, like light, following the inverse square law over astronomical distances would seem to involve either 0% interaction, 100% propagation and/or no medium ? (magnetism is a somewhat more complex effect that does not simply follow the inverse square rule anyway).
Non-emission physics theories, like Maxwell's field theory and Einstein's continuum theory, include inverse square action perhaps non-necessarily and even arbitrarily ? Also in a Gilbert type theory a constant signal-response time, a signal saturation level and/or a maximum response level might replace Einstein's perhaps anomalous constant velocity of light ?
Collision push-theories of forces like gravity are assumed to work something like 'billiards averaged' - where the typical collision is glancing-collision where a ball from one direction collides causing another ball to move away at some angle, but the average being exactly head-on causing the other ball to move away in the same direction though happening much less often. However, signal response systems may always respond precisely to the directionality of incoming signals - as some plants and animals respond to a light source, moving directly towards or directly away or eg spiralling towards like moths. Of course individual 'force events' may perhaps never be detectable, only average responses ?
When a beam of light hits a sheet of glass, a wave theory or a particle theory may seem to require that the light be entirely reflected or entirely refracted - but in fact at least normally some of BOTH happens. While either light theory can be elaborated to explain such double-happening, it seems maybe simpler to take it as not being down to either form of mechanical contact but as down to marginal attraction/repulsion responses Gilbert-Newton theory fashion ? Of course Gilbert, Descartes, Newton and Einstein all supported determinist theories where if you know the full details then any event will involve single determinate outcomes though a multi-event event might have multiple single determinate outcomes. They all rejected probabilistic or indeterminate events in physics as being 'uninformed' or 'inadequately experimented' events only. Yet for some kinds of 'probabilistic' events mathematical laws have been produced that some see as giving an alternative type of. or elaboration of, physics theory.
The 1900 S.P.Thompson english translation of De Magnete was a very impressive book, a giant red hardback measuring about 18 inches by 12 inches and 6 inches thick and a great weight. A very impressive science book to maybe match religions best holy books, but regretably still a poor science translation.
Gilbert's 'De Mundo....'
De Magnete was published in non-Catholic 1600 England before the death in 1603 of both Gilbert and a somewhat sympathetic Queen Elizabeth. Yet he was rightly afraid to publish his ideas on astronomy and
gravity in his lifetime and that, apparently aided by suppression by Sir Francis Bacon, ensured that it was nearly 50 years after his death
before they were published in a version of his De Mundo in Latin in a non-Catholic Holland.
That work showed that Gilbert concluded that there must be some force natural to planetary bodies, which was proportional to their mass, mutually attractive and decreased with distance. An attractive force that was emitted from the sun making planets orbit it, that was emitted from the Earth making the moon orbit it, and that was emitted from the moon making Earth tides. Basically just what astronomy needed. He did not link that planetary force either with magnetism or with earths gravity, though saying that objects weight consist only them responding to attractions from another body like the earth. The version of De Mundo published was not specifically approved by Gilbert and included some sections that may have been mere 'musings'. It came from preliminary draft manuscripts and gave his signal attraction physics as applying much more widely than De Magnete indicated, to include stuff like planet and universe motions, Earth tides and weather effects and probable chemistry and medicine effects. And physics does undoubtedly actually have such wide effects. Gilbert's attraction physics necessarily includes signal emission, signal transmission, signal reception and signal response, possibly subject to some affects by the environs giving variation in some physical signal forces, the published De Mundo did not go further into these details than De Magnete.
Kepler did learn of these astronomy ideas of Gilbert, as least in general, long before their posthumous publishing. He did acknowledge Gilbert but developed an unworkable mechanical-field vortex modification as his own theory (akin to the later Descartes fluid-ether vortex theory) which he wrongly thought better than Gilbert's theory. Newton later disproved Kepler's theory.