Massey Hall
Dalton’s Inscrutable Instrumentality
While it is quite certain that John Dalton was born in a small thatched cottage in the village of Eagles field, Cumberland, England, what is less certain is the day and date of his birth as his family never recorded it properly in the family bible (the way it used to be done those days). However, much later in life, he was told that it was September 5th, 1766. His family had been Quakers for a long time. His Grandfather had converted to this religion in about 1695, about the time he got married. Dalton's father inherited an estate of about 60 acres and married a local Quaker girl, Deborah Greenup. John Dalton grew up working in the fields and in the family shop where cloth was made. His sister used to sell stationery in her own small shop, but despite all these sources of income they were relatively poor due to which the boys could not get much formal education.
Fortunately, John Dalton did get a basic grounding in reading, writing and arithmetic at the nearest Quaker school, which meant that his family was doing better than most others which is evident from the fact that in Dalton's time only about 1 in 200 people used to be literate. At the Quaker school, called Pardshow Hall, one teacher, namely John Fletcher, inspired this young Quaker boy to take up solving mathematical problems, a skill he quickly mastered. This brought him to the attention of a number of people, including a rich Quaker, Elihu Robinson, who mentored him in mathematics, science and meteorology.
Another person who inspired, instructed and then mentored John Dalton was the blind son of a wealthy Kendal merchant who was very interested in a range of scientific subjects, including optics. John Gough clearly had a significant influence on John Dalton, as the first two books that Dalton published were dedicated to his this friend and mentor. One suggestion that Gough made to Dalton was to keep a daily log of the weather and meteorological observations. So he started writing down what he saw and what he measured about the weather patterns in a book, every day. He kept this journal for his entire life, and probably the very last thing he did on the day he died, was to make his final entry.
After a failed attempt to start a school in his home town of Eagles field, John Dalton eventually went into partnership with his brother and in 1785 took over a different school in Kendal where the brothers offered a range of subjects including languages, mathematics and science courses. Despite the school's popularity, they had 60 pupils at one point, and the school could not make money. At this point Dalton had to write answers to "ladies questions" in magazines to make needed extra income. To make money he gave public lectures and even offered to sell his extensive, eleven volume botanical collections to a local museum, but it was John Gough who in 1793 pulled a few strings and got him placed as a tutor at Manchester College where he earned 80 pounds a year. He had wanted to become a physician, but his family persuaded him to choose science instead.
Manchester was probably the second largest town in England at that time, and was rapidly becoming the industrial center of the world. This is where the famous "industrial revolution" started and the town boasted colleges, libraries and lots of other intellectual stimulants. Dalton joined the Manchester Literary and Philosophical Society and immediately published his first book on Meteorological Observations and Essays. In this book Dalton laid out for the first time his ideas on gasses, and that in a mixture of gasses, each gas exists independently of each other gas and acts accordingly. Here his famous ideas had started to form. But after six years as a college tutor he went private. He gave up the post at the college and offered to tutor individual students privately at the sum of two shillings a session. This allowed him much more time to conduct his own research.
It was a good move, as he was able to think and perform a series of experiments at this time that led him to propose the "law" or partial pressures of gasses, which he published in an work entitled Experimental Essays on the Constitution of Mixed Gases; on the Force of Steam or Vapor from water and other liquids in different temperatures, both in vacuum and in air; on Evaporation; and on the Expansion of Gasses by Heat. Here he explained to the world that if two gasses were mixed together they behave as if they were totally independent of each other. The first gas does not attract or repel the second gas; it just behaves as if the second gas did not exist. The result of this "independence" was that the total pressure exerted by the mixture of gasses was the sum of the separate pressures exerted by each part in the mixture. He was also able to show that the environment had a measurable affect on the pressure shown by his gasses, and that there was a mathematical relationship between the pressure of a vapor and its ambient temperature.
Not all gasses interact harmlessly, as Dalton discovered. In 1803 he began to react a gas called nitric oxide (NO) with oxygen to produce a third type of gas. Strangely the result could come out in one of two ways depending on the proportions, or ratios, of the reacting gasses. Using one set of conditions it looked like nitrogen was combining with oxygen in the ratio 1 to 1.7, but at other times, in the ratio 1 to 1.3. By August 1803 he had the answer to this puzzle - the "law of multiple proportions" which stated that the weights of elements always combine with one another in ratios that were always whole numbers. In this way, Dalton was able to start working out a table of atomic weights based on the lightest element, hydrogen, having the arbitrary value of 1.
He expressed his ideas about the make up of gasses this way, "we may form an idea of this by supposing a vessel filled with small spherical leaden bullets among which a quantity of fine sand is poured. The balls are to the sand as the particles of bodies are with respect to the caloric; with this difference only, that the balls are supposed to touch each other, whereas the particles of bodies are not in contact, being retained at a small distance from each other by the caloric."
While forming the mental images of the physical composition of gasses, Dalton struggled to find words and images; he could use to express his ideas. He found two solutions. From his reading of ancient texts, particularly those of Hindu origin, he found the term "atom eater" used by the author Kanda to describe discontinuous matter. Also that the philosopher Democritus had once described water as mostly empty space with smooth balls gliding over each other. The "balls" he called atoms. Newton also contributed the idea that “God in the beginning formed matter in solid, massey, hard, impenetrable, moveable particles”
This made Dalton propose that all matter was made up of hard round particles, which he called 'atoms', and that each type of atom, or element, such as hydrogen, oxygen, nitrogen, etc., differed from the next only by its weight. Thus the atomic theory had been born. But his next idea “how to represent this idea symbolically so that tiny, invisible particles could be 'seen' and their combining properties studied” was equally important. The solution to Dalton was to draw circles, each circle representing one of his tiny atomic spheres. Each element could be distinguished by the contents of the circle, thus:
Using this symbolic representation of invisible atoms, their combining properties could be drawn out, played with, thought about, revised and corrected. It was the perfect way of creating a 'laboratory' where atoms could be moved around at will and placed in a series of relationships that could then be confirmed or denied by actual experiments or data. Today scientists are very comfortable with the idea of model building, and using real or computer models to help them prod and poke around an idea. But in Dalton's day this concept was a major breakthrough when the union of atoms into higher order structures could also be represented.
So chemical reactions could be studied on paper to see if they conformed to observed fact. A way was open that would take the messy mystery out of the nature of physical matter and make it possible to study its properties and behaviors in a rational and mathematical way.
On October 21st, 1803, Dalton stood before the Manchester Literary and Philosophical Society, of which he was now the Secretary, and announced to the world the relative weights of the atoms. This fundamental breakthrough in science did not go un-noticed, and he was immediately invited to repeat his announcements before the Royal Institution of London, before a much larger and much more distinguished audience. The word was out, and Dalton's atomic theory began to receive much publicity and debate.
While scientists like Thomas Thomson and William Hyde Wollaston accepted the concepts at once, some were skeptical for as long as 60 years. However, Charles William Eliot of Harvard University was still not convinced when teaching his classes in 1868. While some were down right hostile; Davy was fanatically opposed and even went as far as to mock the "tall, gaunt, awkward scholar" as Dalton was described by the father of William J. Mayo (who was one of Dalton's pupils).But as more and more experimental work confirmed the theoretical work, even Davy in later life (about 50 years later) was forced to admit that Dalton was right and that all matter was atomic in nature.
Many historians think that Dalton chose to study gasses because of his interest in meteorology, a life long interest in which he collected over 200,000 observations. He used to be involved in his work to the tune that even when trying to relax, Dalton could not, as he remained ever conscious of keeping records.
Unfortunately but in accordance with its firm tradional commitment, not to recognize the champions of its cause, the then elite society never cared to take care of its hero who remained poor through out his life. Having no other means to meet his two ends, Dalton had no option but to teach arithmetic to private students to make a living even after completing more than 60 yearly rounds of his measurable but thoughtful life. Having realized the need of the time some of his sincere friends rose to the call of their conscience and tried to get him a modest pension from the Government, but were told by one of the horses at the helm of affairs "it would be attended with great difficulty". It took a lot of begging and pleading and that too by many influential persons to convince Lord Grey's government to finally provided a modest means of support for one of its more innovative scientists, though hesitantly and reluctantly. Amazingly, it was only 150 pounds a year.
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