Physicist, chemist, theologian, politician and Anglo-American philosopher, born at Fieldhead (in the parish of BBC, near Leeds, belonging to the County of York, Great Britain) March 13, 1733 (or the 24th of the same month and year according to the Gregorian calendar adopted by the English in 1751), and died in Northumberland (Pennsylvania, United States of America) on February 6, 1804. Wanted to bring the associationism is well known in the history of the enlightenment thought by the clearly materialistic conclusions psycho-physical of Hartley (1704-1757); In addition, it reached notoriety among the scientists of his time by his research on the oxygen and other gases, which turned him into a direct forerunner of Lavoisier (1743-1794). In fact, is considered the discoverer of oxygen and other many gases, such as ammonia, the HCL, sulphur dioxide, carbon monoxide and the laughing gas. In his double role as scientist and thinker, Priestley defended a universal monism of the forces that the physical and psychic forces are two parallel and complementary aspects of a single material substance. He/She was also a prominent political supporter of the encyclopedic, liberal and supporter of the ideals of the French Revolution (1789-1799).
Came to the world in a modest rural family, formed by Jonas Priestley, leather Tanner, and María Swift, daughter of herders and farmers. Being the eldest of the six children that had this marriage, was soon sent to the farm of his maternal grandparents, so that it criase under his tutelage while their parents were responsible for the rest of the offspring.
When completing nine years of age, after having been orphaned of mother, the small Joseph returned to the family home and, within days, was in the care of his aunt Sarah, sister of his father. The husband, Mr. John Keighly, was a man of critical spirit and liberal spirit, who used to receive in your home all the dissenting citizens with political ideology and moral religious that was in vogue in England in the first half of the 18th century.
The open mind of Joseph Priestley, who stayed in the House until her aunt died in 1764, was forged in this breeding ground. Encouraged by the stimulus of their tutors, during his childhood he/she studied hard all the disciplines that were part of the basic academic training from a good student of his time, and was noted for its special ability to learning Greek, latin, and even Hebrew. Then, conceived the idea of devoting itself to the religious life; but, in his adolescence, a serious lung ailment (probably tuberculosis) forced him to drop out of school temporarily and to postpone their project become pastor and theologian.
As soon as he/she had recovered his health, he/she returned with greater enthusiasm to intellectual activity, and in a short period of time, learned perfect French, Italian, German, Syrian, Arabic and Chaldean, at the time that guy in the study of geometry, algebra and other areas of mathematics. With this splendid experience under his belt, he/she returned to conceive the idea of studying theology, even though by then already beginning to seriously question some dogmas of the Calvinist faith that their elders had bequeathed.
Before these doubts, decided to renounce membership in the Academy in Mile End, where it remained a strictly Calvinist dogma, and enrolled, on the other hand, in the Daventry Academy, famous at the time for its liberal ideology. There, the young Joseph Priestley had occasion to become familiar with the scientific experimentation and other customary practices of physicists, chemicals, and scholars from the natural sciences (botanists, zoologists, etc.); but far from discarding your old project studying theology, he/she deeply at the same time in their religious studies and it eventually became Minister of the Calvinist Church.
Thus, after having graduated in Daventry, went on to manage the spiritual Congregation of Needham Market (in Suffolk), where it would remain for three years. During all that time, questions about Calvinism continued to torment him, by which the exercise of your pastoral ministry, then ' you a rougher time, at the time that caused him a great unpopularity among members of your community (which soon detected weak beliefs). Hence, Priestley decided to break radically with Calvinism and embrace the faith of Unitarianism, another Protestant doctrine that, as a main distinctive feature against the others, denies the existence of the Holy Trinity and has as basic pillars reason, freedom and religious tolerance (principles that fit to perfection the encyclopedic, in those yearsI was already succeeding in France).
It became, as well, to lead the spiritual life of the parish of Nantwich (in Cheshire), composed of faithful ones much more liberal and tolerant. There felt so at ease that it was able to provide valuable services to the community, which in turn resulted in numerous offers so he/she exercised as teacher and different youth-private tutor. With this work, Priestley managed to gather a certain amount of money that allowed him to go to acquiring different materials for study and research, and also won a notable teaching reputation, which eventually helped him to enter, as a Professor of classical languages at Warrington Academy, other educational institutions who enjoyed great prestige by its liberal ideology. There he/she spent six years that the own Priestley always recalled among the happiest of his working life; and, far from being limited to the kinds of languages, it became very popular among his students and peers for their lessons and lectures on political issues, on historical facts related to his own time, on advances and discoveries of science of the time and the great English classical authors of previous centuries, such as Shakespeare (1564-1616) and Milton (1608-1674).
In 1762, when he/she still lived in his uncles House, scientist and humanist of Fieldhead married Mary Wilkinson, daughter of one of the big promoters of revolution Industrial in the United Kingdom, John Wilkinson (1728-1808). By that time, in the course of their regular visits to London, began a friendship with the key figures of the rational encyclopedic, as Richard Price - author of the pamphlet Civil Liberty (liberty Civil), which is said that directly influenced the drafting of the Declaration of the independence of America - or the American Benjamin Franklin (1706-1790), then in the British capital with the purpose of presenting the independence claims of the colonies.
It was Franklin who, astonished by the scientific research that is self-learning, had made Priestley, encouraged him to publish his book entitled The History and Present State of Electricity (history and present state of electricity, 1767), at the time that encouraged membership in the Royal Society (which took place in 1766). This first scientific work, of great interest to physicists and other specialists in the study of electricity, proved to be too complex for the reader half; for that reason, Priestley, always moved by this desire to own their master status populariser, decided to offer a simpler version, enriched with illustrations that could clarify some concepts too arid. And, whatever that not found in your environment any capable artist reflect what explained in his treatise, the own Priestley - by gala, once more, of his amazing versatile wise - learned to basic techniques of perspective and made the illustrations in this version elementary in the history of electricity. It was, in addition, in the course of this artistico-cientifico work, the first to use India as a material rubber used to delete the marks that the pencil on the paper, so it is considered since the inventor of the rubber eraser.
Their dependent family members, increased during that decade of the 1960s, was forced to leave the Academy of Warrington to accept a new religious office of high rank, spiritual director of the congregation or parish of Mill Hill; and so, in 1767 settled with his family in Mill Chapel (in Leeds), a territory which knew perfectly, because it was very close to his place of birth.
Thereafter it began to study gases and air, with special attention to the theory of the Phlogiston which, at the beginning of the 18th century, had enunciated Georg Ernst Stahl (1660-1734). According to this theory, all metals were composed of lime and Phlogiston, a principle that is exuded from them during combustion (and that could again be transferred to metals, for example in the form of charcoal, so was considered a transferable reagent). Priestley, who was not a great theorist of physical and chemical research, but if a great cultivator of experimental science, departed from the theory of the Phlogiston of Stahl, which believed firmly, to end up obtaining, in 1774, what initially called air desflogisticado (i.e., oxygen, name that soon would give the same substance(, the aforementioned Lavoisier).
The method used by Priestley in obtaining his desflogisticado air is not too complex: imbued with the original idea of Stahl, proceeded to concentrate the Sun's rays through a lens on a sample of mercuric oxide; then it was seen that combustion caused by the heat of these rays effect, it appeared a gas in which the flame of a candle burned with vivacity (a circumstance that was, precisely, that led him to call him "air desflogisticado"). In addition, noted that the resulting lime this process, which he/she called mercurius precipitatus per, had greater weight.
Although, as you have already stopped it it foresees higher, Lavoisier was really who grasped the true importance of this gas (which changed its name because, in his opinion, tallied him more the Greek oxigenium, which means "Begetter of acids" voice), Priestley was the first to discover that green plants give off oxygen and need light to grow.
In addition to oxygen, Priestley discovered ammonia, carbon monoxide, the hydrogen sulfide (or hydrogen sulphide), sulphur dioxide, nitrogen and Silicon Tetrafluoride. Part of his research and experiments on these and other gases were reflected in his work and Experimens observations ondifferent kinds of air (experiments and observations on different kinds of air, 1772). Although, it may seem a trivial circumstance, to Priestley helped him much in their discoveries about the oxygen the proximity of his house a large industry that was beer; There he/she could make important observations about the gas and air bubbles, which also related to their experiences in some natural spas where water flowed with effervescence.
This observations allowed him to fabricate, in 1772, an instrument which he/she called "pneumatic channel" or "pneumatic trough", with which it was easy to collect fumes water-soluble - until then, very difficult to obtain-, and also the dissolved in mercury. With this and other works, it is not surprising that the already referred experiment conducted in Wiltshire on August 1, 1774, in which, using the heat of the Sun's rays, managed to detect your air desflogisticado (which, in his own words, seemed it was "five or six times better than common air") for the first time would be successful.
Consecrated, thanks to this find, as one of the great scientific figures of his time, Priestley wanted to enlist, shortly afterwards, in the third expedition of famed Navigator and scientific adventurer James Cook (1728-1779). But the expedition members rejected for fear that the firm religious beliefs of Fieldhead scholar sembrasen the rifts between the members of the voyage that was meant to discover and explore a narrow so-called northern latitudes, which cross the American continent to put in communication the Atlantic with the Pacific.
Priestley was not overcome by disappointment that caused you this rejection, and insisting on further expanding its vital and intellectual horizons accepted the post of tutor particular of the sons of the Earl of Shelburne (1737-1805), who had rigged a substantial remuneration; In addition, the brilliant scientist held his own home in Calne (the summer residence of the Shelburne family in Wiltshire), and set, among other very advantageous working conditions, being able reconcile their duties of instructor with vocational dedication to science and to the study of the Humanities at all times.
During the Decade of the 1970s, Priestley wrote some of his most notable works, coinciding with its stage of higher delivery to the studies of physics and chemistry. Among them, and aside from the aforementioned book dedicated to electricity, listed the titled Disquisitions Relating to Matter and Spirit - that exposed its materialist conception of human existence - and Experiments and Observations - where you left printed a detailed relationship of its main achievements in the field of chemistry.
More and more entrenched in his position as private tutor of the offspring of one of the most linajudas families of the United Kingdom, Joseph Priestley, by getting of the sinsabor that had caused him not to travel with Cook, he/she accompanied Lord Shelburne on a long tour of Europe. During the prolonged stay in Paris, came into contact with the figures most notable French intellectuals of the time, including Lavoisier, who was aware of his discovery of the aires desflogisticado; Thanks to these first-hand reports, French scientist made little after significant findings on the oxygen and other gases.
On his return to the United Kingdom, Priestley, always open to new expectations, amicably broke labor and affective ties that linked him to the Shelburne family (which, in gratitude for services rendered, granted him a life pension) and resumed his pastoral work, now at Fairhill, enclave located close to Birmingham. There he/she settled, in 1780, with his family, consisting then by his wife Mary, his three sons and only daughter. Thanks to the fortune of the Wilkinson - and, in particular, of his brother-in-law John, Priestley bought a House on property and it established not only the headquarters of his new pastoral ministry, but also of his particular laboratory and study center. There, soon surrounded himself with educated men and entrepreneurial spirits that showed great curiosity about science, engineering and technological innovation, such as the Potter Josiah Wedgwood - which got him much of the utensils with which was riding his laboratory-, entrepreneur and patron Matthew Boulton - who had become rich with the exploitation of its famous factory of buckles and buttons -, and engineer and James Watt (1736-1819) - Scottish mechanic who, thanks in part to the money contributed by Boulton, worked tirelessly in the construction of the first steam engine. In that circle of entrepreneurial scientists and engineers also included Erasmus Darwin - paternal grandfather who was to formulate the theory of the evolution of the species--and William Small - who had been Professor of the American Thomas Jefferson (1743-1826), future third President of the United States of America, in the prestigious William and Mary College.
In Birmingham, Joseph Priestley joined also the Lunar Society (Lunar Society), in which, in addition to the already mentioned Darwin, Watt and Boulton, used to appear from time to time, as a guest of honor, Benjamin Franklin, an old acquaintance of the scientist of Fieldhead. The members of this society - popularly known as "lunatics" - used to gather to discuss topics related to astronomy and the natural sciences, although they also liked to engage in animated discussions of literary and philosophical. Cited once a month in the House of one of them, always a full moon Monday (to facilitate the return of others to their respective homes).
Priestley is focused, at that time, in his role as theologian and thinker, which resorted to write some works as notable as Letters to a Philosophical Unbeliever (letters to a kaafir philosopher)-in which defended the natural religion of the attacks launched against it by the skepticism of David Hume (1711-1776); History of the Corruptions of Christianity (history of the corruptions of Christianity) - in which attacked frontally against the basic tenets of Christian orthodoxy, particularly against the doctrine of the Holy Trinity —; and History of the Early Opinions Concerning Jesus Christ (the first user story about Jesus Christ),-where he/she was denying the dogma of the divine Trinity, showing that it was not included in any passage of Scripture. Logically, the dissemination of these three works brought serious problems to the author, who was harshly criticized in the pulpits, accused of heresy in the House of Commons and checked, even by the more retrograde of "agent of Satan".
Joseph Priestley and other practitioners of Unitarianism - religious doctrine that does not recognize in God rather than a single person - were deprived of British citizenship and the rights corresponding to them as citizens of the United Kingdom, while his expulsion from the country was not forced. To emphasize the difficulties that crossed by those dates, scholar and scientist of Fieldhead publicly declared supporter of the French Revolution, and arrived to take an active part, on July 14, 1791, in a dinner at which is commemorated at Birmingham the storming of the Bastille, and in which the congregants celebrated the "emancipation of twenty-six million people from the yoke of despotism".
Local, enraged crowd with religious beliefs and political opinions of Priestley, attacked their properties and destroyed his house and his laboratory, setting fire to their belongings (including his magnificent library and the precious Manuscripts preserved in it, some of them unpublished). The scientist and his family managed to flee, rescuing from the furious attack only clothes that day wearing sunsets. After a year - specifically, the day 26 of August of 1792 - in response to a request for granting of French citizenship to all the philosophers who had distinguished himself by defending the freedom, the Assembly of France awarded citizenship Joseph Priestley, Jeremy Bentham, Williarn Willberforce, David Williams, N. Gorain, Anacharsis Cloots, Corneille Pauw, Henri-Joachim CampeN. Pestalozzi, Thaddeus Kosciusko, Friedrich Schiller, George Washington, Thomas Paine, James Madison and Alexander Hamilton.
After the destruction of their properties, Priestley vowed never return to Birmingham. Took refuge first in London, and from there went to live, for a brief period, in Tottenham. Then, looking for even greater anonymity and discretion, he/she settled in Hackney. Publicly condemned by the House of Commons, Priestley was persecuted and reviled in pulpits, posters and newspaper articles, humiliated in rhetoric and cartoons, and harassed by threatening letters. The campaign against his figure reached proportions of such gravity that the Royal Society came to expel him from their ranks due to the pressure exerted against by many of their most conspicuous member.
In this situation, children - who felt so harassed, until the end to see how refusing them the right to work in their own country - decided to emigrate to the United States of America. Prestley - that it was no longer English citizen and felt frankly disappointed by his former fellow - decided to join them despite his advanced age; and so, on April 7, 1794, at sixty-one years, he/she embarked with his wife and children heading to a new world where he/she would spend the rest of his life.
Upon landing in New York, Priestley had the opportunity to confirm the wise decision of yours leave a revolt, angry and rarefied Europe, because he/she knew that, during its naval journey, Lavoisier had been guillotined in the Parisian Place de la révolution. Is New York, the Priestley quickly switched to Philadelphia, where the old scholar took the decision to return to preaching, to continue to spread their unitary creed. It rejected a Professor of chemistry who offered to him by the University of Pennsylvania and settled in the small town of Northumberland, to the North of the State, where he/she founded a colony of English dissenters. He/She returned there to meet an important library and founding his own laboratory, where he/she continued to perform studies and experiments of great depth; but the death of his younger son (Harry), followed quickly by his wife, deeply overshadowed his last years.
As founder of the Unitarian Church of America, Joseph Priestley exerted a remarkable influence on the social life of the United States at the end of the 18th century and beginning of the next century (came to be appointed Director of the Presidente Jefferson, which featured his religious and educational advice). By that time, he/she spent winters in Philadelphia, where, in addition to the social recognition enjoyed, was the subject of several tributes for his scientific and humanistic work (among them, that offered the American Philosophical Society). From 1801, he/she fell seriously ill, but not interrupted why its inexhaustible inactivity religious and intellectual, as evidenced by the fact that continue drafting articles and reviewing his writings up to the last moments of his life. Finally, the death surprised him on February 6, 1804, when he/she was correcting their papers.