Comments for en-gb 30 Mon 29 Dec 2014 07:01:28 GMT+1 A feed of user comments from the page found at Jane pps Sitting in the garden slurping on the wine which rewards the efforts of dealing with my jet spray force of a son, it occurred to me that IOT isn't just about what it includes but what it excludes...and that is also what elevates it above everything else for me. Fri 21 May 2010 21:22:56 GMT+1 Jane A refreshingly unpretentious communication of information thank-you...and some interesting listeners' comments. Henry Cavendish was in a position to utilize his bright intelligence fruitfully. However, the programme made me ponder what the equation for untapped human latency, throughout time, might look like. How many brilliant minds have been lost to the potato field. Come to think of it, many amongst us must have school reports laying testament to our own personal input! Best wishes - Jane ps I nearly always post a comment because this programme lifts me up, without fail, every single week. It's partly the content, partly Melvyn and his guests...and partly something that's difficult to define. Truly grateful I am! Fri 21 May 2010 20:27:01 GMT+1 Andrew Clegg Years ago, one of the things that persuaded me to take up chemsitry as a career is that my teacher was able to recite most of what is below from memory. It refers to the extraordinary analysis of air carried out by Cavendish, published in Phil Trans 1785 which refers to the annoying little bubble always left over at the end every time he repeated the experiment. It was 100 years later that Rayleigh 'discovered' argon. ... As far as the experiments hitherto published extend, we scarcely know more of the nature of the phlogisticated part of our atmosphere, than that it is not diminished by limewater, caustic alkalis, or nitrous air; that it is unfit to support fire, or maintain life in animals; and that its specific gravity is not much less than that of common air; so that, though the nitrous acid, by being united to phlogiston, is converted into air possessed of these properties, and consequently, though it was reasonable to suppose that part at least of the phlogisticated air of the atmosphere consists of this acid united to phlogiston, yet it might fairly be doubted whether the whole is of this kind, or whether there are not in reality many different substances confounded together by us under the name of phlogisticated air......I then, in order to decompound as much as I could of the phlogisticated air which remained in the tube, added some dephlogisticated air to it, and continued the spark till no further diminution took place. Having by these means condensed as much as I could of the phlogisticated air, I let up some solution of liver of sulphur to absorb the dephlogisticated air; after which only a small bubble of air remained unabsorbed, which certainly was not more than 1/120th f the bulk of phlogisticated air let up into the tube; so that if there is any part of the phlogisticated air of our atmosphere which differs from the rest, and cannot be reduced to nitrous acid, we may safely conclude, that it is not more than 1/120th part of the whole. Fri 21 May 2010 16:25:26 GMT+1 John Thompson Henry Cavendish,”the richest of the learned and the most learned of the richest”, possibly had Asperger’s Syndrome,but that should not detract from his achievements.His experiments with airs led him to find the 1st element that is a gas(hydrogen),thatwas colourless, tasteless,invisible,and it was inflammable:he called it inflammable air,different to the air we breathe.He believed it to be the mysterious ‘Phlogiston’.He didn’t realize he’d isolated a new element.He wasn’t credited with hydrogen during his lifetime.But he did observe something that would play a crucial role in our understanding of the natural world.Each time he set light to the gas,a dewy liquid began to appear on the surface of the glass, water.This struck right to the heart of the ancient concept of 4 elements,where water was believed to be an element.But if you can make water out of 2 other constituents it couldn’t be an element.In fact water is a compound. Cavendish’s observations could have shaken the foundations of accepted belief,but he was thrown off-course by Phlogiston.He reckoned the airs must contain a form of water,modified by the presence of Phlogiston.It didn’t occur to himwater was a compound.While he was close to destroying the temple of the ancient 4 elements,he couldn’t quite disprove them.The pillars of that temple now stood on shakey ground,soon to come crashing down.It wasn’t Cavendish’s water that would disprove the ancient theory,it was air.By the 1700s,there were 3 known types of air or gases: the common air we breathe,inflammable air(now known as hydrogen) and fixed air,or carbon dioxide.Joseph Priestly experimented with these airs.He found oxygen by heating mercuric oxide,butbecause he believed in Phlogiston,he thought the splint was introducing Phlogiston to the new air and catching fire.He concluded his air must be without Phlogiston,and called it dephlogisticated air.Priestly knew he’d found something special,but didn’t realize he’d isolated an element.He inadvertently told Lavoisier about his experiment in France.In Lavoisier’s experiments, inflammable air became hydrogen,and Priestly’s dephlogisticated air became oxygen.Lavoisier had demolished the Phlogiston theory,the red herring that had hampered British chemistry for a century.It didn’t exist!As your speaker said,Oxygen means ‘acid bringer’, Hydrogen means ‘water-former’.It was also Lavoisier who transformed chemistry from a collection of disparate factsinto a science with unified principles.He was the 1st scientist to define an element,any substance that could not be split into simpler components by chemical reactions, listing no fewer than 33 of them,dividing them up into 4 categories:gases,non-metals,metals, earths.He realized neither water nor air is an element,although he thought heat and light were.He named the 2 constituents of water,hydrogen and oxygen.Thankyou for doing such a good show. Thu 20 May 2010 17:23:28 GMT+1 Annie-Lou Surely Henry Cavendish was more than just shy and eccentric. He was autistic. OK, I know what you're thinking, lately its become fashionable to retrospectively diagnose all sorts of historical figures with ASDs, and sometimes its implausible to say the very least.But in the case of Henry Cavendish, we must consider his obsessive attention to detail, his total focus, his antisocial tendancies which went way beyond shyness. He communicated with his staff only in writing and was apparently known to literally run away if someone called to see him. And (here's the give away) people meeting him were told not to make eye contact but to speak "as if to the air" and wait to see if he would respond or just walk away!Add to this his lack of interest in publishing his work or getting public recognition and I think we can say he was definitely "on the spectrum". Thu 20 May 2010 08:49:33 GMT+1