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Penicillin -

In one of the most famous flukes in history, the father of antibiotics, Alexander Fleming, was simply trying to study the growth of Staphylococcus aureus bacteria.

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Penicillin -

When he came back some weeks later to check on the progress of the bacteria's growth, he realized its growth had been inhibited by our good friend, the mold Penicillium notatum.

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The pacemaker -

The lifesaving pacemaker was originally meant to be a simple listening device, that would have been used to record the sounds of the heart.

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Viagra -

When the "little blue pill" was first being developed in 1989, its inventors didn't have bedroom problems in mind. They were trying to develop a treatment for a heart condition called angina.

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Viagra -

When Viagra entered its testing phase, it soon became clear that it was mostly useless as a guard against angina, but it was very useful for its current well-known use.

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The pacemaker -

Its unsuspecting inventor, Wilson Greatbatch, mistakenly used the wrong transistor when building his prototype, and discovered that his creation couldn't record sound, but it did, in fact, emit electrical pulses very similar to that of the heart.

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Super glue -

Before super glue became an indispensable part of any good repair kit, it was met with a notable lack of enthusiasm when it was first invented in 1942.

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Super glue -

Its inventor, Harry Coover, was trying to develop a clear plastic he could make affordable rifle sights out of, in order to profit off of the war effort. Coover regarded the impossibly sticky substance as useless until nine years later, when he patented the mixture as "Superglue."

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The microwave -

The first microwave patent was filed by American inventor Percy Spencer in 1945, but it wasn't exactly his life's work. Spencer was simply working with magnetron vacuums, which produce microwaves, when he realized the candy bar in his pocket had inexplicably melted.

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The microwave -

Upon further investigation, Spencer discovered the cooking power of microwaves, which are now an essential part of most kitchens.

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Safety glass -

French author, artist, and chemist Edouard Benedictus was playing around in his lab when he accidentally knocked a glass flask off his table. Benedictus looked down expecting to see glass shattered across the floor, but what he saw changed the world.

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Safety glass -

The flask had countless fractures running through it, but was still in one piece. After some investigating, Benedictus realized this strange phenomenon was caused by what had previously been in the flask: cellulose nitrate. This chemical, which still coated the inside of the flask, kept it from shattering, and Benedictus introduced safety glass to the world.

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Sticky notes -

The light and gentle adhesive that makes sticky notes so handy actually came from a total failure in the 3M company's endeavors into inventing a super adhesive.

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Sticky notes -

The weak mixture was disregarded by its primary inventor, Spencer Silver, but one Arthur Fry picked it up later when developing a bookmark that would stick to book pages without damaging them.

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X-ray machines -

In 1895, German physicist Wilhelm Rontgen was testing whether or not cathode could pass through glass when he noticed a board in the room, coated with chemicals, was emanating a soft, green glow.

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X-ray machines -

After some more tinkering, Rontgen discovered the wonderful power of x-rays that allowed him to see his bones when his hand was placed in front of the glow.

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Matches -

John Walker, a 19th-century English chemist, was hard at work trying to develop a sort of incendiary paste that could be used in guns. What he invented instead were matchsticks.

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Matches -

While Walker was mixing chemical ingredients for what he hoped would be a type of gun paste, he absentmindedly scraped his wooden mixing spoon against his hearth and the utensil burst into flames. Walker quickly capitalized on this phenomenon, and introduced what he called "Friction Lights" to the world in 1826.

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Brandy -

Brandy was invented by a Dutch shipmaster in the 16th century who was looking for a way to make wine more transportable. One of his ideas was to distill wine into a concentrate, so that one could add water to rejuvenate the wine at the end of the journey.<

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Brandy -

It soon became apparent, however, that the distilled version of the wine was delicious on its own; certainly far more delicious than watered-down wine concentrate. And so, brandy was born and marketed as brandewijn, or "burnt wine."

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Vulcanized rubber -

Charles Goodyear, of Goodyear tires fame, is credited as the inventor of vulcanized rubber, which is far more resistant to weathering and heat than normal rubber.

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Vulcanized rubber -

His discovery wasn't intentional though. Goodyear accidentally dropped a mixture of normal rubber and sulfur onto a stove, and only then realized that the substance was so durable.

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Botox -

Ophthalmologist Alan B. Scott, looking for a way to correct chronically crossed eyes, took a leap of faith when he decided to inject a form of botulism toxin into his patient's forehead.

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Botox -

To the relief of both patient and doctor, the treatment was successful, but there was an added, unexpected bonus that has made Botox that wildly popular product that it is today: the wrinkles around the eyebrow and forehead of the patient seemed to magically disappear.

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Silly putty -

Silly putty would go on to make waves in the toy market for simply being weird and gooey. But the man who invented it was searching for an entirely different material.

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Silly putty -

James Wright, a Scottish engineer during World War II, was hoping to find a cheap substitute for synthetic rubber when he accidentally dropped boric acid into silicone oil. This new and nutty material was of course useless to the war effort, but later made Wright a pretty penny in the toy market.

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Anesthesia -

During the 1800s, nitrous oxide was known as laughing gas, and was everyone's favorite party partner. The gas would induce a short-lived state of euphoric delirium that caused both users and audiences alike to laugh uncontrollably.

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Anesthesia -

A few people, in the midst of their delirious delight, managed to harm themselves in their surroundings without even realizing it or feeling the pain. This was noticed by a dentist, who turned the party drug into one of the earliest and most effective forms of anesthesia. 

Sources: (Best Life) (Treehugger) (Interfocus)

See more: Inventors who came to regret their inventions

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