William Henry Perkin
One serendipitous discovery came from a young scientist who began his career earlier than most. A career that heralded a new dawn for modern chemistry. At first sight, this is a fairly unremarkable photograph. You can see it’s of a young boy, William Henry Perkin, in Victorian clothes, it’s framed quite nicely. It’s only when you start to understand the story behind the photograph that it becomes very interesting indeed.
This is a self-portrait of a 14-year-old boy. He took it in 1852, which is only just over 10 years after the invention of photography. So photography was still experimental at this time. And he would have had to have an array of quite complex chemicals in his house.
So given the quality of this photograph, then that makes him a very precocious individual indeed. His name is William Perkin. He was the son of an East End carpenter.
His father must have recognised his talent, or at least valued education, because just one year later, at the age of 15, he was sent to the Royal College of Chemistry to learn chemistry. To become what we’d now call a scientist. We know he had an enquiring mind, not because he took the picture, but because of what he did just four years later.
When he started his career, William Henry Perkin was living in exciting times. This was the age of Empire. A world where in time, the sun really would never set on British imperial assets. But as the empire expanded, so, too, did the risk to Britain’s colonialists as they were exposed to deadly tropical diseases such as malaria.
Fortunately, there was relief available for malaria in the form of a drug called quinine. But it could only be extracted from the bark of the cinchona tree, which grows on the remote eastern slopes of the Andes, making it expensive and difficult to get hold of.
What was needed was a more reliable and cheaper source.
So the young William Henry Perkin was set to work to find a way to make synthetic quinine in the lab.
This is a mock-up of what Perkin did. I’m not using the real chemicals because they are dangerous, but the idea is simple and the logic is impeccable.
So this is quinine, the white powder that William Henry Perkin wanted to make. Now, he knew that this was made of carbon, nitrogen, oxygen and hydrogen, and he also knew the proportions. So he reasoned like this.
Why don’t I take something simpler an amine, actually an amine called aniline, which is a ring of carbons with a nitrogen and a couple of hydrogens stuck on the end. So it’s everything you need, apart from the oxygen. He then took this, potassium dichromate, which is a strong oxidising agent.
Now, today, we know that this rips electrons off things, but Perkin thought that it added oxygen. And so, you see what he wanted to do? He wanted to take a simple compound with carbons, nitrogens and hydrogens, and mix them together with something that stuck oxygens on and produce quinine.
So… he just dissolved this potassium dichromate in solution, dissolved some amines in dilute sulphuric acid, turned the tap, mixed them together… heated them up, and waited.
And at the end of the experiment, what he got was a muddy, black mess. In other words, apparently, the experiment had failed.
Had William Henry Perkin been working in a modern commercial environment, he might well have stopped here. But what happened next is a prime example of why the inquiring mind must be given the freedom to explore and knowledge should never be lost.
What it’s thought is that Perkin just decided to go back, cleaning up the apparatus after making this dark sludge, but what he noticed is that the residue seemed to colour whatever it touched purple.
So being a good experimental chemist, he decided to investigate further. So he took that residue, and this is actually a real sample of that chemical, and he started trying to purify it to investigate it, to understand its properties.
So he mixed it with petroleum and then he makes it with ethanol. And if I just dab a bit of cloth into this… then it dyes it bright purple. So Perkin had discovered a dye which he called mauveine.
Perkin’s dye was far superior to anything created by nature, and one that could be mass produced at a fraction of the cost. It quickly gained popularity after Queen Victoria appeared at her daughter’s wedding in a silk gown dyed with mauveine.
Thanks to William Henry Perkin, the 1890s are now affectionately known as the Mauve Decade.
But it didn’t stop there. Synthetic dyes have been brightening our lives ever since. Perkin helped usher in the dawn of organic chemistry. A new age of products, from plastics to perfumes and medicines.
The interesting thing about William Perkin is that if he’d set out with the aim of discovering a new purple dye, then he probably would have failed. And if he hadn’t been a curious scientist wanting to understand why his experiment didn’t seem to work, then again, he would have probably failed to discover that dye.
Perkin’s story is a warning of the potential perils of targeted research. Had he been working in a commercial environment, it’s likely that because the purple dye wasn’t quinine, his further investigations would have been thought to be an expensive waste of time. So though targeted science appears to give us what we want, there is the very real chance that it can mean we miss out on unexpected discoveries.
There have always been arguments about the purpose of science. Whether its primary role should be the pure pursuit of knowledge, or whether its main value is in the application of science to solving problems that improve our lot, serving society. It’s a balancing act and one that hasn’t always been easy to get right.