HE is one of medicine's greatest unsung heroes who saved the life of a teenage girl when he performed the world's first ever successful brain tumour removal at the Glasgow Royal Infirmary in 1879.

It was a monumental achievement in the history of neuroscience and one that sparked a war of words with elitist London colleagues who resented this "outsider" Scot from the Isle of Bute overtaking them in the field.

Yet most people today - even in Scotland - have never heard of William Macewen.

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As the 140th anniversary of that landmark operation approaches on July 27, the Glasgow Science Festival hopes to change that with an event celebrating Macewan's contribution to brain surgery.

The 'Great Minds: Innovations Brain Surgery' talk will take place at the Royal College of Physicians and Surgeons Glasgow on June 13, with presentations from two of his biggest fans: consultant neurosurgeon Roddy O'Kane, and retired neurologist Professor Ian Bone.

HeraldScotland: Barbara WatsonBarbara Watson

The patient who enabled 28-year-old Macewen to make history was Barbara Watson, 14, from Campsie, who was admitted to hospital with a swelling over her left eye.

"She would have died if she hadn't been operated on," said Bone.

"She was having seizures that were starting in her face and spreading into her arm.

"Macewan had read all of these papers and he knew that the tumour, or whatever it was, must be on the third convolution of the frontal lobe.

"This is 20 years before the X-ray was invented, it's 100 years before the CT scan was invented, so these guys in that era had nothing other than their clinical judgement to decide where to make a hole and how to operate.

"But Macewen had done all his homework. He knew exactly where to go."

The surgery was performed at 11pm using chloroform for anaesthesia and a corkscrew-like device called a trephine to "core out" a hole in her skull, enabling Macewan to remove the malignant growth from the surface of her brain.

HeraldScotland: Prof Ian BoneProf Ian Bone

Macewen, who had studied medicine at Glasgow University and trained under antiseptic pioneer Joseph Lister, used carbolic acid to sterilise his instruments and his patients.

But he also went further and actually washed his hands before surgery - something unusual among doctors in his day.

Barbara, who had previously had a tumour removed from behind her eye, made a full recovery from her brain surgery and survived another four years before dying of kidney disease.

HeraldScotland: A trephine, the device used to 'core' holes in the skull in the 1870sA trephine, the device used to 'core' holes in the skull in the 1870s

It should have been front page news, but the operation barely registered until five years later when a group of London surgeons - among them Lister's nephew, Rickman Godlee - claimed the triumph for themselves when they removed a tumour from inside a man's brain.

Read more: Paramedic rushed his own baby girl to hospital after braind tumour drama

Although he died 26 days later, it was declared to be the world's first successful brain tumour removal - until Glasgow's medical community struck back.

Bone said: "Macewen was operating in a centre, Glasgow, where most developments in the field of neuroscience were not taking place. He wasn't one of the inner circle - he was an outsider.

"He was reading other people's books and he went ahead and did six operations before 1884 that no one else in the world seems to have done.

"But he was reporting them in things like the Glasgow Medical Journal or to the South Glasgow Medical Society. He wasn't actually presenting his work on the international stage.

"But in 1884, the guys in London did the operation and they did it with all the world's famous neurologists looking on. It was like they were performing in the Albert Hall and Macewen was in a scout hut.

"It got enormous publicity. The London Times ran a big article, and an article was published simultaneously in the Glasgow Herald, that the 'world's first brain operation had been successfully performed'.

"Then the people up here started saying, 'hey what about Macewen? - he's done six of these already and no one's batted an eyelid'.

"Then you get this wonderful correspondence, a lot of it in the Herald, a lot in the Times, with people saying 'this may be new to London, but we've been doing it in Glasgow for years'.

"Then there's a letter back from London saying 'well, people have been doing operations on the brain back into history but not proper operations' and 'your operation done in the Saltmarket doesn't count'.

"So you get this tremendous north-south divide, and what you've also got is a class issue. Because these guys down in London are all well-connected guys, and they're getting all the publicity, all the fame, and Macewen has basically been sidelined.

"Then, after all these letters in the Herald and the Times, Macewen gets invited down to London, gets to sit at a meeting with the great and the good, gets to present his cases, and they very grudgingly admit 'you've done pretty well here'.

"But they don't give him the full acclaim until many years later. And many years later they gradually accept that Macewen was first.

"But by goodness, he had to battle for it."

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The period was marked by seismic shifts in our understanding of the brain in general.

It was nothing new to cut holes in sick humans' skulls - people had been doing it since neolithic times to release 'evil spirits' presumed to be causing mental illness or epilepsy and other neurological conditions.

But by the 1870s, debate over how the brain functioned and how we should research it had reached fever pitch.

There were three competing schools of thought: phrenology, unitary theory, and the localisation theory.

Phrenologists believed that every function - from limb movement to personality - was dictated by the shape of the skull and the scalp.

Advocates of unitary theory believed the brain operated as a whole. For them, the idea that different areas could control different functions undermined the idea of a God-given human spirit.

However, by the early 1870s, localisation - so fundamental to our understanding of the brain today - was gaining support, but hostility to animal research meant experiments were done in secret.

"There was research being carried out on animals where bits of brain were being removed to show that particular areas of the brain carried out particular functions - language, movement and so on," said Bone.

"A lot of this work in the UK on monkeys was carried out very surreptitiously in west Yorkshire, in a lunatic asylum.

"This was carried out there, out of the public eye, because it was a time of the big anti-vivisectionist movement and Queen Victoria was an avid anti-vivisectionist.

"So all this work that led to Macewen's operation was being carried out on monkeys, and dogs and cats, and was gaining a lot of bad publicity.

"But it wasn't until 1881 at an international conference that it was finally accepted that the brain did have areas that carried out specific functions.

"So Macewen was operating before that was accepted wisdom, which was pretty brave."

HeraldScotland: Roddy O'KaneRoddy O'Kane

For Roddy O'Kane, a neurosurgeon at the Queen Elizabeth University Hospital in Glasgow, the workaholic Macewen "typifies a brain surgeon".

"If you look at neurosurgeons today - they all hate it when I say this, but I include myself in it - we are all egotists," said O'Kane. "We are Type A personalities. You have a drive that is also about serving your own ego: look what I can do.

"And society bestows you with this idea that you're really clever - you're like a 'rocket scientist'. It's bulls***, but there's no doubt you're entering a contact sport with the patient and it's still common to hurt them or kill them because you're dealing with very critical structures.

"I always say that doesn't make you clever, it makes you braver. You have to have a resilience - or even a psychopathic tendency - because you have to be able to get up and do it again the next day.

"You can lose heart and I understand why some people can't do it - not for intellectual reasons, but coping reasons.

"In Macewen's era, the prevailing thinking was 'don't dare operate on the brain'. So there is an arrogance in him, but it's a brilliant arrogance, and actually it's an arrogance that still should exist with clinicians if you want to drive things forward."

O'Kane says he still "marvels" at drawings Macewen did mapping out the anatomy of the brain.

"His drawings of cerebral localisation - I still marvel at what he achieved," said O'Kane. "If my trainee could repeat what's in that book they'd be a bloody good neurosurgeon.

"Macewan's book - okay, it doesn't name all the wee blood vessels and details that he couldn't possibly have seen without a microscope - but it's so bloody accurate, and the names for the folds are very similar to what we use today.

"Not only that, he was able to localise where the arm, leg, motor function are on a brain in a paper in the British Medical Journal in 1888. That's jaw-dropping to me."

Although Macewen went on to become Regius Professor of Surgery at Glasgow University and was knighted by Edward VII in 1902, he is often bizarrely overlooked in histories of neuroscience.

In 'The Minds Behind the Brain', an account neuroscience's pioneers, Macewen is described as a "bull in a china shop".

"He gets a few lines, but not an awful lot to be honest," said Bone.

For O'Kane, part of the joy of Macewen is in his low tolerance for fools - and his readiness to stand up to management bean-counters.

"He had a fight when he was working the Royal Infirmary, say about the price of bandages or something, and the manager stood up and said 'we cannot do x, y, z with bandages'.

"Then Macewan stood and said to the chair 'Mr Chairman, can you ask the cabbage not to speak?'.

"Of course the whole room erupts and the chairman says to Macewen, 'you must apologise'. So Macewen says, 'ok, I will apologise, to the cabbage'.

"There's an arrogance about him and it just made me kill myself laughing when I read about it.

"All these things you think are of the modern era - that management exists today to ruin doctors lives, it existed all the time."

Today, brain science is being transformed by technology and tumour genetics which are paving the way to personalised drug treatments, and O'Kane believes Macewen would still have thrived. 

O'Kane said: "Modern neurosurgery is not being made better by surgeons getting better - it's the scientists behind us, and the people developing the technology.

"Technological innovation - use of endoscopes, being able to magnify, being able to use drugs that make tumour glow under ultraviolet light when we're operating.

"I always say, if we have good technology we will advance much faster.

"I think Macewen had that drive to learn and I think he would be relentless in his pursuit of knowledge in the modern era."