You’ve probably heard it a million times before.  Whenever you practice chemistry, you should protect yourself by wearing safety goggles.

At times, however, you may think to yourself: why?  If I know what the outcome of my experiment will be, and I’m using substances I’m familiar with, why do I need to wear goggles at all?

Although it can be tempting to forgo safety in favor or comfort, getting yourself in the habit of wearing goggles every time you do an experiment is a really good idea, and not just because your teacher says so.

Even if you’ve researched your experiment thoroughly, you can never be absolutely certain what the outcome will be.  By anticipating that something unexpected might happen, you are in fact acknowledging one of the best aspects of chemistry: some of the most wonderful discoveries take place when we least expect them.  And because they do, the only way to really keep yourself safe is to prepare for every experiment as if something new (and possibly dangerous!) might happen.

In this post, we’ll explore two examples of accidental discovery from the history of chemistry.  The common thread in each story is a scientist who thought that he was clearly on the path to an expected result, only to discover something unexpected and much more important by mistake.

Purple Dye

At the age of 18, William Henry Perkin made a discovery that made him rich and opened up an entire field of research.  And he did it all totally by accident.

Fascinated by chemistry from an early age, Perkin enrolled in the City of London School at the age of 13.  By the time he was 14, Perkin had written to great physicist Michael Faraday, and began attending his Saturday afternoon lectures.  In 1855, when Perkin was only 17 years old, he had finished his college education at the Royal College of Science and began working as a research assistant under a more established chemist.

His first assignment was to find a way to make a chemical called quinine, which was used as a medicine for malaria.  Quinine was a naturally occurring compound that could be isolated from the bark of a tree, but the process was very time consuming, which made quinine too expensive to be useful as a medicine.

One day, while working on his synthesis, he decided to oxidize a sample of aniline sulfate.  Unfortunately, he didn’t realize that his sample of aniline sulfate was contaminated with another chemical called toluidine.  When he carried out the reaction, he obtained a strange dark colored precipitate—a solid that settles to the bottom of a solution.

When he investigated the precipitate further, he observed a “strangely beautiful” purple color that stained a cloth he had been using to wipe up spills at his workstation.  The dye eventually became known as mauveine, and it was one of the first synthetic dyes.

With Perkin’s discovery, purple became inexpensive and fashionable.

In fact, prior to his discovery, purple dye was harvested from mollusks in the Mediterranean Sea, but the process was incredibly inefficient.  It took thousands of mollusks just to create a single gram of purple dye!  Because the color was so costly to produce, purple garments were a status symbol.  Only very wealthy people could afford them.

As a result of using a contaminated reactant, Perkin accidentally discovered a valuable and important substance.  After his discovery, he found ways to make other synthetic dyes, and went into business selling them.  Perkin made enough money to retire at age 36 and devoted the rest of his life to the study of chemistry.  Although he went on to achieve many things, his single greatest accomplishment in chemistry was an accident.

Phosphorous

Another tale of accidental discovery comes from the history of the element Phosphorous.  Phosphorous, whose name comes from the Latin meaning “light bearer” due to its property of glowing in the dark, was discovered during a period of history when alchemy was thought to be a science .

Alchemists believed that it was possible to change or “transmute” common metals into silver or gold.  Some of them also believed in a mysterious powerful substance called the “Philosophers Stone” which had the power to endow people with eternal youth.

Ironically, although we know today that alchemy is not a real science like physics or biology or chemistry, many of the practitioners of alchemy made important contributions to science in the pursuit of things that didn’t exist.  This is exactly true in the case of Phosphorous.  Its discovery is generally credited to German alchemist Hennig Brand in 1669.

While searching for the fabled philosopher’s stone, Brand collected a white waxy substance that burned brilliantly and glowed in the dark.   It was Phosphorous, and it was one of the first elements that had been discovered since ancient times.  Although he may not have realized it, this discovery was far more important and valuable than the impossible pursuit of alchemy.

Although the scientific method helps us to structure our thinking by starting with a research question, sometimes, as these stories relate, we get an answer to a question we might not even have known to ask.  Sometimes, we discover something important quite accidentally.

And that something might be a lucrative commodity or a glowing curiosity.  It might be an interesting diversion, or it might be a scientific breakthrough.  Because the road to scientific discovery isn’t necessarily a straight one, it’s important to keep our eyes peeled for detours, or recognize when we’ve taken one without realizing it!  If you keep experimenting, you never know what you might find, not only at the end of your inquiry, but along the way.

Just remember to fasten your seatb … er … wear your goggles to keep you safe on the journey.