Here’s the list of top 10 important inventions that were invented through accident or mistakenly lead process.

10. Microwave ovens

Percy Spencer, an engineer from the Raytheon Corporation was conducting a radar-related research project with a new vacuum tube. Spencer realized that the candy bar in his pocket began to melt during his experiments. He then put popcorn into the machine, and when it started to pop, he knew he had a revolutionary device on his hands.

9. Scotchguard

Patsy Sherman, a renowned American chemist, was assigned in a project of developing a rubber material which wouldn’t deteriorate from jet African fuel exposure. Once she dropped a mixture on her shoe and noticed that one spot of her shoe is clean and bright but the rest of it is stained and dirty. Later, with more research and experiment she turned this invention into this famous stain resistant component.

8. Teflon

In 1938, Roy Plunkett, a scientist with DuPont, was working on ways to make refrigerators more home friendly by searching for ways to replace the current refrigerant, which was primarily ammonia, sulfur dioxide, and propane. After opening the container on one particular sample he had been developing, Plunkett found his experimental gas was gone. All that was left was a strange, slippery resin that was resistant to extreme heat and chemicals.

In the 1940s the material was used by the Manhattan project. A decade later it found its way into the automotive industry. It wasn’t until the ’60s that Teflon would be used for its most noted application- nonstick cookware.

7. Matches

For more than 100,000 years, humans have been playing with fire. But no one could create a really easy way to start a fire until a British pharmacist tried to clean his stirring utensil. In 1826, John Walker was stirring a pot of chemicals when he noticed a dried lump had formed on the end of the mixing stick. Without thinking, he tried to scrape off the dried gob and all of a sudden, it ignited.

Walker wasn’t interested in patenting the idea, so Samuel Jones copied the matches and sold “Lucifer.” They were a little more practical than Walker’s friction lights. Lucifers were shorter and came in a smaller cardboard box for easy carrying.

6. Saccharin (an artificial sweetener)

The familiar sweetener in the pink packet was discovered because Constantin Fahlberg, a researcher from Johns Hopkins University, forgot to do what even a high school chemistry student knows- ‘always wash your hands’. He had spilled a chemical on his hands in the lab that caused his bread to taste very sweet. The researcher immediately requested a patent and mass-produced his product.

Luckily for dieters everywhere, he managed not to poison himself along the way.

5. The Pacemaker

The artificial pacemaker is a wonder of modern science. A small, implantable device that regulates a human heartbeat through electrical impulses have saved millions of lives was not meant to be invented. John Hopps, an electrical engineer was conducting research on hypothermia and was trying to use radio frequency heating to restore body temperature. During his experiment, he realized if a heart stopped beating due to cooling, it could be started again by artificial stimulation. This realization led to the pacemaker.

4. X-Ray

Wilhelm Roentgen, an eccentric physicist, was interested in investigating the properties of cathode ray tubes. His experiments involved the passing of electric current through gases at extremely low pressure. On November 8, 1895, while he was experimenting, he observed that certain rays were emitted during the passing of the current through the discharge tube.

His experiment that involved working in a totally dark room with a well-covered discharge tube resulted in the emission of rays which illuminated a barium platinocyanide covered screen. The screen became fluorescent even though it was placed in the path of the rays, two meters away from the discharge tube. A week after his discovery, Roentgen took an X-ray photograph of his wife’s hand which clearly revealed her wedding ring and her bones.

3. Plastics

Can you imagine carrying water bottles made of clay or using disposable utensils made of eggs and animal blood? The legend of the discovery of plastic says that were it not for two accidents, those might be the materials we’d be stuck with today.

The started in the lab of Charles Goodyear, who combined rubber and sulfur and accidentally put it on the stove for a period of time. When he came back, he found a tough and durable material–created through a process eventually called vulcanization.

2. Anesthesia

Without this second last accidental discovery on our list, medical treatments would be a big pain for sure.

Crawford Long, William Morton, Charles Jackson, and Horace Wells all come to mind when talking about anesthesia. These men realized that in some cases, ether and nitrous oxide (laughing gas) inhibited pain in people under their influence.

One example, in particular, demonstrates the accidental discovery of these compounds used to prevent pain in the medical field. In 1844, Horace Wells attended an exhibit and witnessed a participant injure his leg while under the influence of laughing gas. The man, whose leg was bleeding, told Wells that he didn’t feel any pain. After that scientists started applying anesthesia for dental treatments and further developed the revolutionary medicine.

1. Penicillin

Sir Alexander Fleming was searching for a “wonder drug” that could cure diseases. However, it wasn’t until Fleming threw away his experiments that he found what he was looking for. One day, Fleming noticed that a contaminated Petri dish he had discarded contained a mold that was covered in colonies of bacteria, except in one area where a blob of mold was growing. When he grew the mold by itself, he learned that it contained a powerful antibiotic, penicillin. Around the mold was an area free of bacteria, as if the mold had blocked the bacteria from spreading.

From that minor act of scientific sloppiness, we got one of the most widely used antibiotics today.