The Birth of Chemistry

When was chemistry born? When did the history of chemistry start? Well, in some way you could say it starts at the moment the first atoms form after the big bang, or when the first hydrogen atoms join to form a hydrogen molecule. Or you could say, from a human perspective, that the history of chemistry starts when humans begin to actively transform their surroundings, like when making fire, where carbohydrates are converted into carbon dioxide and water. Perhaps you could also say that the history of chemistry starts with the Bronze Age. It lasted from around 3300 to 500 BC. Bronze is an alloy, a combination of two metals, in this case copper and tin. What's nice about bronze is that its melting point is lower than the melting point of copper, but it is still harder. Thanks to this, bronze is easier to use for weapons or tools. And, as you can see from this beautiful bronze lure, more than 2000 years old, it stays pretty good. The Bronze Age was followed by the Iron Age. How long the Iron Age lasted differs quite a lot. It was last to arrive in the Nordic countries, and was followed by the In southern Europe around 580, and in the Nordic countries some 300 years later. During the Iron Age, humans learned to make tools from iron instead of bronze. The iron was recovered from pieces of bog iron, like this one. The bog iron contains iron ore, a kind of iron oxide. When the ore is burned together with charcoal, a chemical reaction between the carbon and the oxygen in the ore takes place, forming carbon dioxide. What remains is more or less pure iron, with some carbon content remaining. By forging the iron you get different qualities, which you could use for nails or plows or, well, yes, swords too for that matter. So, from this point of view, chemistry was used in a very practical way. But chemistry, you've already learned, is the science about how matter changes, and you can also think of this from a theoretical point of view. One of the very first people to do this was a Greek philosopher called Thales. He lived around 625-545 BC and came from Miletus in present Turkey. Thales is sometimes considered the father of philosophy, and one of the reasons for this is because he pondered upon what the world is really made of. He noted that water can change in a number of ways as you already know. It passes from ice, to liquid, to water vapor, and then back again. Therefore, he reasoned, the water is the permanent entity, the single substance which forms everything else. Now, this isn't correct, and perhaps Thales himself would have realized this if he had made any experiments. But almost none of the classical philosophers made any experiments. Instead, they praised the ideas or the thoughts. The word philosopher itself means a person who loves thoughts. Physical work was something that only slaves performed, and so experiments weren't something that a highly regarded philosopher was concerned with. But if you don't examine if your ideas match what happens in reality, things often go wrong. An exception from this was the philosopher Empedocles. There were a lot of myths surrounding him, for example that he could talk to animals. It's also said that he claimed to be divine, and to prove this, he would jump into molten lava, and then jump back up again. You quickly realize what happened. He jumped down, but never went up again, unfortunately. Anyway, Empedocles actually showed by experiment that air isn't empty space, but some kind of matter. You can try this out yourself, and I'm sure you already have if you've had soda with a straw before. Try inserting the straw into the soda. Cover the top of the straw with your finger, and remove the straw from the soda. The soda stays in the straw, and doesn't pour out until you release your finger. In the same way, you can cover the top of the empty straw, and insert it into the soda again. The soda doesn't enter the straw until you release your finger again. This is because, as I said, the air is not empty space, but instead some kind of matter. This was the conclusion that Empedocles drew, a conclusion that he developed into the theory that everything is made of water, air, earth, and fire. Of course, this isn't correct either, but still, that idea held for something like 2000 years. Before I explain why it was like that, I would like to talk about another Greek philosopher, Democritus. The very first atomic theory is usually attributed to him. He had this remarkable idea that perhaps there exists some indivisible small particle. His reasoning went something like this. Imagine that you have an apple. If you cleave it, you have two parts. If you cleave it again, you have four, then eight, and so on. At one point, you will end up with a particle that is so small that you cannot divide it further. Then you end up with something that is indivisible, or atomos in Greek. This was the first atomic theory. But, of course, Democritus's ideas would not stand unchallenged. One of the most common arguments against him was that if everything is made up of some kind of small marbles, how then can things hover? How can we have air? Shouldn't the air in that case simply sink to the ground like sand in the wind? Two very important Greek philosophers were Plato and his student Aristotle. You can see them in the center of this fresco by Raffaello, the school of Athens. Plato and Aristotle were immensely influential, and if any of them said that things were a certain way, it was considered absolute truth. And they both have ideas, and wrote about physics, chemistry, and biology, but most of it was just fiction, which had nothing to do with reality. Because, as I said, the philosophers never made any experiments. That is, they never tested if their ideas were consistent with reality. Anyway, Plato and Aristotle thought that it was reasonable that matter consisted of water, air, fire, and earth. So that was what was thought for something like 2000 years. And that was the end of that. In the Middle Ages, the age of alchemy, there were even those who meant that one should absolutely not pursue knowledge, just keep what was already known. Therefore, European monks devoted themselves to giving science, so to speak, artificial respiration by laboriously copying all the classic scriptures. Instead, science flourished in the Arabic part of the world, and for us chemists above all, a man called Jeber is interesting. With apologies for my pronunciation, his entire name was Abu Musa Jabir ibn Hayyan, but in the western world he is best known as Jeber. And it is actually from his name that we've got algebra, Al-Jeber, which shows what an extremely influential scientist he was. What the chemist Jeber is most known for is that he developed many of the apparatuses and methods that are still used by modern chemists. Here you can see some of the apparatuses for distillation and heating that he used. What Jeber devoted himself to was called alchemy, and in alchemy it's not always clear what is science and what is magical or mystical. But even if the alchemists sometimes saw themselves as sorcerers, they contributed by developing the chemical methods. Sometimes a man called Henning Brand is considered the last alchemist. Yeah, I right should have been, because the dream of making gold still lives on with some mystics. Because that was typically what the alchemists sought. Making gold, or the philosopher's stone, a magical stone which would turn lead into gold, and according to some myths, could also give eternal life. In one of his experiments in 1669, Henning Brand discovered the element phosphorus while trying to make gold. Urine is yellow, so perhaps he thought urine had something to do with gold. He concentrated several liters of urine and then distilled it. This gave him a substance that in an almost magical way gave off light. Henning Brand called it phosphorus, after a Greek word that means bearer of light. If Henning Brand was the last alchemist, Robert Boyle was the first chemist. In 1661, that is eight years before Henning Brand discovered phosphorus, he published a book called The Skeptical Chemist. As you can see, he got rid of al in alchemy, and with that all of the magical and mystical stuff. Boyle meant that chemistry must be built on experiments and conclusions drawn from those experiments. So what were the experiments that Boyle himself made? Well, as a matter of fact, Boyle was the first one to describe the difference between mixtures, pure substances and chemical compounds. He also made experiments with gases, and discovered using this vacuum pump that sound needs a medium for propagation. He then drew the conclusion that matter, for example air, must be made of tiny particles that push each other as the sound propagates. Another important milestone in the history of chemistry was the discovery of Since I'm Swedish, I must mention that the Swedish chemist Carl Wilhelm Scheele discovered oxygen around 1771. But the Englishman Joseph Priestley was the first to publish his findings, which is what counts in the world of science. But even if Priestley is credited with discovering oxygen, it was another chemist who gave it its name. It was Antoine Lavoisier, the most prominent chemist of the time who did that. The working-class Yorkshire man Priestley showed his newly discovered good air to the nobleman Lavoisier, and Lavoisier quickly realized its importance. Lavoisier called the new air oxygen, which means something that creates acids. This is because many oxides have an acidic taste. Before oxygen was discovered, it was thought that Thanks to the discovery of oxygen, Lavoisier could perform precise measurements on what happened during combustion, and could draw the conclusion that during combustion, the fuel and oxygen react, forming new substances. Oh yeah, and he also discovered hydrogen, described the conservation of mass during chemical reactions, helped develop the metric system, wrote a list of all known elements, and quite a few other things as well. Lavoisier was not only a nobleman, but also very rich and hated. Because of this, he was beheaded during the French Revolution at the end of the 18th century. The last chemist I wish to mention here is yet another Swede, Jöns Jacob Berzerius. He lived between 1779 and 1848, and he made huge progress in the field of chemistry. One could say that he You see, when he wrote a textbook on chemistry for his students at the Karolinska Institute, he gave the chemical elements the symbols we still use today. H for hydrogen, C for carbon, N for nitrogen, and so on. He also introduced a novel way to write chemical formulas, essentially the way we still write them today, like H2O for water and so on. While he was at it, he also coined the terms catalysis, polymer, protein, and a few more. Last but in no way least, he compiled a list of atomic weights of all the then known elements. This proved very valuable. With the help of that list, Mendeleev could construct his first periodic table. But that I'll talk more about in the next video. And before I leave you, don't forget to learn on Mr. Enge's chemistry and to check your learning. You'll find a link in the description.