Question: What year did scientist William Gilbert propose electricity and magnetism were distinct effects?
About the article "Electromagnetism", section "Classical electrodynamics".

Candidate passages:
The 16th century marked the beginning of scientific understanding of electricity and magnetism that culminated with the production of electric power and the industrial revolution in the late 19th century.
In the 1550s, English scientist William Gilbert spent 17 years experimenting with magnetism and, to a lesser extent, electricity.
For his work on magnets, Gilbert became known as "The Father of Magnetism."
His book "De Magnete" quickly became the standard work throughout Europe on electrical and magnetic phenomena.
He made the first clear distinction between magnetism and what was then called the "amber effect" (static electricity).
In 1663, German physicist Otto von Guericke created the first electrostatic generator, which produced static electricity by applying friction.
The generator was made of a large sulfur ball inside a glass globe, mounted on a shaft.
The ball was rotated by means of a crank and a static electric spark was produced when a pad was rubbed against the ball as it rotated.
The globe could be removed and used as an electrical source for experiments with electricity.
Von Guericke used his generator to show that like charges repelled each other. 
The scientist William Gilbert proposed, in his "De Magnete" (1600), that electricity and magnetism, while both capable of causing attraction and repulsion of objects, were distinct effects.
Mariners had noticed that lightning strikes had the ability to disturb a compass needle, but the link between lightning and electricity was not confirmed until Benjamin Franklin's proposed experiments in 1752.
One of the first to discover and publish a link between man-made electric current and magnetism was Romagnosi, who in 1802 noticed that connecting a wire across a voltaic pile deflected a nearby compass needle.
However, the effect did not become widely known until 1820, when Ørsted performed a similar experiment.
Ørsted's work influenced Ampère to produce a theory of electromagnetism that set the subject on a mathematical foundation.
A theory of electromagnetism, known as classical electromagnetism, was developed by various physicists over the course of the 19th century, culminating in the work of James Clerk Maxwell, who unified the preceding developments into a single theory and discovered the electromagnetic nature of light.
In classical electromagnetism, the electromagnetic field obeys a set of equations known as Maxwell's equations, and the electromagnetic force is given by the Lorentz force law.
One of the peculiarities of classical electromagnetism is that it is difficult to reconcile with classical mechanics, but it is compatible with special relativity.
According to Maxwell's equations, the speed of light in a vacuum is a universal constant, dependent only on the electrical permittivity and magnetic permeability of free space.
This violates Galilean invariance, a long-standing cornerstone of classical mechanics.
One way to reconcile the two theories (electromagnetism and classical mechanics) is to assume the existence of a luminiferous aether through which the light propagates.
However, subsequent experimental efforts failed to detect the presence of the aether.
After important contributions of Hendrik Lorentz and Henri Poincaré, in 1905, Albert Einstein solved the problem with the introduction of special relativity, which replaces classical kinematics with a new theory of kinematics that is compatible with classical electromagnetism.
(For more information, see History of special relativity.
)In addition, relativity theory shows that in moving frames of reference a magnetic field transforms to a field with a nonzero electric component and vice versa; thus firmly showing that they are two sides of the same coin, and thus the term "electromagnetism".
(For more information, see Classical electromagnetism and special relativity and Covariant formulation of classical electromagnetism.
Electricity would remain little more than an intellectual curiosity for millennia until 1500When the Italian scientist Girolamo Cardano started a study on electricity in De Subtilitate (1550), distinguishing for the first time the electric strength from the magnetic one.
In the 1600 the English scientist, William Gilbert extended the study of Cardano on electricity and magnetism, distinguishing the lodestone effect from static electricity produced by rubbing amber.
He coined the New Latin word "electricus" ("of amber" or "like amber", from "ήλεκτρον" ["elektron"], the Greek word for "amber") to refer to the property of attracting small objects after being rubbed.
This association gave rise to the English words "electric" and "electricity", which made their first appearance in print in Thomas Browne's "Pseudodoxia Epidemica" of 1646.
Further work was conducted by Otto von Guericke who showed electrostatic repulsion.
Robert Boyle also published work. 
Magnetic attraction was once accounted by Aristotle and Thales for as the working of a soul in the stone.
After the lapse of centuries, a new capacity of the lodestone became revealed in its polarity, or the appearance of opposite effects at opposite ends; then came the first utilization of the knowledge thus far gained, in the mariner's compass, leading to the discovery of the New World, and the throwing wide of all the portals of the Old to trade and civilization.
In the 11th century, the Chinese scientist Shen Kuo (1031–1095) was the first person to write of the magnetic needle compass and that it improved the accuracy of navigation by employing the astronomical concept of true north "(Dream Pool Essays", AD 1088 ), and by the 12th century the Chinese were known to use the lodestone compass for navigation.
In 1187, Alexander Neckam was the first in Europe to describe the compass and its use for navigation.
Magnetism was one of the few sciences which progressed in medieval Europe; for in the thirteenthcentury Peter Peregrinus, a native of Maricourt in Picardy, made a discovery of fundamental importance.
The French 13th century scholar conducted experiments on magnetism and wrote the first extant treatise describing the properties of magnets and pivoting compass needles.
The dry compass was invented around 1300 by Italian inventor Flavio Gioja.
Archbishop Eustathius of Thessalonica, Greek scholar and writer of the 12th century, records that "Woliver", king of the Goths, was able to draw sparks from his body.
The same writer states that a certain philosopher was able while dressing to draw sparks from his clothes, a result seemingly akin to that obtained by Robert Symmer in his silk stocking experiments, a careful account of which may be found in the 'Philosophical Transactions,' 1759.
Italian physician Gerolamo Cardano wrote about electricity in "De Subtilitate" (1550) distinguishing, perhaps for the first time, between electrical and magnetic forces.
Toward the late 16th century, a physician of Queen Elizabeth's time, Dr. William Gilbert, in "De Magnete", expanded on Cardano's work and invented the New Latin word "electricus" from "" ("elektron"), the Greek word for "amber".
Gilbert, a native of Colchester, Fellow of St John's College, Cambridge, and sometime President of the College of Physicians, was one of the earliest and most distinguished English men of science — a man whose work Galileo thought enviably great.
He was appointed Court physician, and a pension was settled on him to set him free to continue his researches in Physics and Chemistry.
Gilbert undertook a number of careful electrical experiments, in the course of which he discovered that many substances other than amber, such as sulphur, wax, glass, etc., were capable of manifesting electrical properties.
Gilbert also discovered that a heated body lost its electricity and that moisture prevented the electrification of all bodies, due to the now well-known fact that moisture impaired the insulation of such bodies.
He also noticed that electrified substances attracted all other substances indiscriminately, whereas a magnet only attracted iron.
The many discoveries of this nature earned for Gilbert the title of "founder of the electrical science".
By investigating the forces on a light metallic needle, balanced on a point, he extended the list of electric bodies, and found also that many substances, including metals and natural magnets, showed no attractive forces when rubbed.
He noticed that dry weather with north or east wind was the most favourable atmospheric condition for exhibiting electric phenomena—an observation liable to misconception until the difference between conductor and insulator was understood.
Gilbert's work was followed up by Robert Boyle (1627—1691), the famous natural philosopher who was once described as "father of Chemistry, and uncle of the Earl of Cork."
Boyle was one of the founders of the Royal Society when it met privately in Oxford, and became a member of the Council after the Society was incorporated by Charles II.
in 1663.
He worked frequently at the new science of electricity, and added several substances to Gilbert's list of electrics.
He left a detailed account of his researches under the title of "Experiments on the Origin of Electricity".
Boyle, in 1675, stated that electric attraction and repulsion can act across a vacuum.
One of his important discoveries was that electrified bodies in a vacuum would attract light substances, this indicating that the electrical effect did not depend upon the air as a medium.
He also added resin to the then known list of electrics.
This was followed in 1660 by Otto von Guericke, who invented an early electrostatic generator.
By the end of the 17th Century, researchers had developed practical means of generating electricity by friction with an electrostatic generator, but the development of electrostatic machines did not begin in earnest until the 18th century, when they became fundamental instruments in the studies about the new science of electricity.
The first usage of the word "electricity" is ascribed to Sir Thomas Browne in his 1646 work, "Pseudodoxia Epidemica".
The first appearance of the term "electromagnetism" on the other hand comes from an earlier date: 1641.
"Magnes", by the Jesuit luminary Athanasius Kircher, carries on page 640 the provocative chapter-heading: ""Elektro-magnetismos" i.e.
On the Magnetism of amber, or electrical attractions and their causes" ( "id est sive De Magnetismo electri, seu electricis attractionibus earumque causis"). 
Gilbert was born in Colchester to Jerome Gilberd, a borough recorder.
He was educated at St John's College, Cambridge.
After gaining his MD from Cambridge in 1569, and a short spell as bursar of St John's College, he left to practice medicine in London and travelled on the continent.
In 1573, he was elected a Fellow of the Royal College of Physicians.
In 1600 he was elected President of the College.
From 1601 until her death in 1603, he was Elizabeth I's own physician, and James VI and I renewed his appointment.
His primary scientific work—much inspired by earlier works of Robert Norman—was "De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure" ("On the Magnet and Magnetic Bodies, and on the Great Magnet the Earth") published in 1600.
In this work, he describes many of his experiments with his model Earth called the terrella.
From these experiments, he concluded that the Earth was itself magnetic and that this was the reason compasses point north (previously, some believed that it was the pole star (Polaris) or a large magnetic island on the north pole that attracted the compass).
He was the first to argue, correctly, that the centre of the Earth was iron, and he considered an important and related property of magnets was that they can be cut, each forming a new magnet with north and south poles.
In , he argues in support of diurnal rotation, though he does not talk about heliocentrism, stating that it is an absurdity to think that the immense celestial spheres (doubting even that they exist) rotate daily, as opposed to the diurnal rotation of the much smaller Earth.
He also posits that the "fixed" stars are at remote variable distances rather than fixed to an imaginary sphere.
He states that situated "in thinnest aether, or in the most subtle fifth essence, or in vacuity – how shall the stars keep their places in the mighty swirl of these enormous spheres composed of a substance of which no one knows aught?
"The English word "electricity" was first used in 1646 by Sir Thomas Browne, derived from Gilbert's 1600 New Latin "electricus", meaning "like amber".
The term had been in use since the 13th century, but Gilbert was the first to use it to mean "like amber in its attractive properties".
He recognized that friction with these objects removed a so-called "effluvium", which would cause the attraction effect in returning to the object, though he did not realize that this substance (electric charge) was universal to all materials.
In his book, he also studied static electricity using amber; amber is called "elektron" in Greek, so Gilbert decided to call its effect the "electric force".
He invented the first electrical measuring instrument, the electroscope, in the form of a pivoted needle he called the "versorium".
Like others of his day, he believed that crystal (quartz) was an especially hard form of water, formed from compressed ice:Gilbert argued that electricity and magnetism were not the same thing.
For evidence, he (incorrectly) pointed out that, while electrical attraction disappeared with heat, magnetic attraction did not (although it is proven that magnetism does in fact become damaged and weakened with heat).
Hans Christian Ørsted and James Clerk Maxwell showed that both effects were aspects of a single force: electromagnetism.
Maxwell surmised this in his "A Treatise on Electricity and Magnetism" after much analysis.
Gilbert's magnetism was the invisible force that many other natural philosophers, such as Kepler, seized upon, incorrectly, as governing the motions that they observed.
While not attributing magnetism to attraction among the stars, Gilbert pointed out the motion of the skies was due to earth's rotation, and not the rotation of the spheres, 20 years before Galileo (but 57 years after Copernicus who stated it openly in his work "De revolutionibus orbium coelestium" published in 1543 ) (see external reference below).
Gilbert made the first attempt to map the surface markings on the Moon in the 1590s.
His chart, made without the use of a telescope, showed outlines of dark and light patches on the moon's face.
Contrary to most of his contemporaries, Gilbert believed that the light spots on the Moon were water, and the dark spots land.
Besides Gilbert's "De Magnete", there appeared at Amsterdam in 1651 a quarto volume of 316 pages entitled "De Mundo Nostro Sublunari Philosophia Nova" (New Philosophy about our Sublunary World), edited—some say by his brother William Gilbert Junior, and others say, by the eminent English scholar and critic John Gruter—from two manuscripts found in the library of Sir William Boswell.
According to Dr. John Davy, "this work of Gilbert's, which is so little known, is a very remarkable one both in style and matter; and there is a vigor and energy of expression belonging to it very suitable to its originality.
Possessed of a more minute and practical knowledge of natural philosophy than Bacon, his opposition to the philosophy of the schools was more searching and particular, and at the same time probably little less efficient."
In the opinion of Prof. John Robison, "De Mundo" consists of an attempt to establish a new system of natural philosophy upon the ruins of the Aristotelian doctrine.
William Whewell says in his "History of the Inductive Sciences" (1859):Gilbert, in his work, "De Magnete" printed in 1600 has only some vague notions that the magnetic virtue of the earth in some way determines the direction of the earth's axis, the rate of its diurnal rotation, and that of the revolution of the moon about it.
Gilbert died in 1603, and in his posthumous work ("De Mundo nostro Sublunari Philosophia nova", 1631) we have already a more distinct statement of the attraction of one body by another.
"The force which emanates from the moon reaches to the earth, and, in like manner, the magnetic virtue of the earth pervades the region of the moon: both correspond and conspire by the joint action of both, according to a proportion and conformity of motions, but the earth has more effect in consequence of its superior mass; the earth attracts and repels, the moon, and the moon within certain limits, the earth; not so as to make the bodies come together, as magnetic bodies do, but so that they may go on in a continuous course."
Though this phraseology is capable of representing a good deal of the truth, it does not appear to have been connected... with any very definite notions of mechanical action in detail.
Gilbert died on 30 November 1603 in London.
His cause of death is thought to have been the bubonic plague.