Britain’s Victorian era — defined by the reign of Queen Victoria, from 1837 to 1901 — was a time of great scientific discovery. In this period, Charles Darwin’s theory of natural selection laid the groundwork for evolutionary science and all of modern biology, while Scottish physicist James Clerk Maxwell’s theory of electromagnetism set the stage for the discoveries of Albert Einstein and other great physicists of the 20th century. But the Victorian age was also marked by some scientific beliefs that were, shall we say, a bit less theoretically sound. In fact, some of the commonly held beliefs of this time are downright shocking in the context of our modern understanding of the world. Here are six Victorian-era “scientific” beliefs that were more than a little off the mark.

Diseases were caused by bad smells

Before people had a firm grasp of germ theory, the conventional belief among everyday people and scientists alike was that diseases were caused by foul odors, or noxious “miasma,”that were emitted from rotting organic matter and traveled through the air to cause infections. Disease-prevention measures in Victorian England often took the form of eliminating bad smells rather than treating contaminated water for pathogens. Miasma theory was gradually replaced with germ theory as the dominant scientific explanation for illness around the 1870s, when scientists such as Louis Pasteur and Robert Kochprovided experimental evidence that microorganisms — and not the unpleasant odors they produced — were responsible for infectious diseases.

Nearly any ailment could be cured by an electric shock

The advancements in electrical science that occurred during the Victorian age led to some remarkable inventions, such as the telegraphand the electric lightbulb. But they also led to some overenthusiastic and misguided beliefs about the power of electricity to do, well, pretty much anything — including heal the body of just about any ailment imaginable. The latter half of the 19th century saw the proliferation of household inventions meant to administer electric shocks to the user. Devices as varied as electric hair brushes, electric corsets, and electric suspenders began finding their way into Victorian households, all promising to improve people’s health by providing them with a sturdy jolt of electricity. The most prominent of these “electrotherapy” devices was the electropathic belt, which was studded with diodes that users placed directly onto their skin to provide themselves with small shocks throughout the day. Needless to say, these contraptions produced minimal health benefits.

The eyes of a murder victim could reveal an image of the killer

In the second half of the 19th century, it was commonly believed that the retina of a deceased person carried the image of the last thing they saw in life as a permanent imprint known as an “optogram.” Forensic scientists even theorized that the optograms of murder victims could bear the image of their killers, and could therefore be used to solve crimes. The belief in optograms was so widespread that particularly careful criminals would destroy their victims’ eyeballs to prevent investigators from extracting an incriminating image. Though optograms have been thoroughly debunked by modern science, the belief in their utility as a crime-solving tool persisted all the way into the 1920s.

The shape of your skull determined your personality

Phrenology, the belief that a person’s personality was determined by the contours of their skull, is one of the most infamous pseudoscientific beliefs of the Victorian era. Bumps on the skull were said to predict everything from whether a person was predisposed to be “secretive” to whether they were destined to become a killer. One of the uglier applications of phrenology was as a tool to “scientifically” justify the racist beliefs of the era. This has earned phrenology a reputation as not just bad science, but a potential tool of oppression, too.

Telepathy could transmit healthy thoughts

Many medical professionals in Victorian England believed in the power of “thought transference,” or telekinesis, and its ability to transmit healthy thoughts into the mind of a suffering patient to alleviate mental anguish. Thought transference was even actively studied by the scientific establishment: In 1882, a group of British researchers founded the Society for Psychical Research, which was dedicated to applying scientifically rigorous study to supernatural phenomena, including mind transfer. Numerous scholarly articles were published on the efficacy of telekinesis, including a lengthy treatise on the scientific principles of moving objects with one’s mind.

An advanced civilization had built an irrigation system on Mars

In 1877, the Italian astronomer Giovanni Schiaparelli discovered the presence of long, winding markings on the surface of Mars. Schiaparelli called these markings “canali,” or “channels.” However, many English speakers had mistranslated the word as “canals” — a word that suggests artificial origin. One overenthusiastic American astronomer named Percival Lowell took this idea and ran with it; he published several books arguing that the markings were evidence of a complex irrigation system built by an advanced civilization on the red planet. Lowell’s theories generated widespread public excitement and he led a successful career as a lecturer expounding upon his theories of Mars as an “abode of intelligent constructive life.” While Lowell’s ideas captivated the Victorian public, his theories were thoroughly debunked by the time of his death in 1916 — but not before his depictions of Martian “canals” helped cement the planet in the public imagination as a potential home for extraterrestrial life.