SO far, Lindsey Fitzharris tells me, two people have fainted during her book tour. Actually, one of them, a man, keeled over twice.

"He fainted during my book trailer," she explains. "My friend is a film-maker and we filmed this incredible reconstruction of a pre-anaesthetic, pre-antiseptic operation and I think that's what did him in."

If anything, Fitzharris seems rather pleased at this reaction. We are sitting in the Surgeon's Hall Museum in Edinburgh, surrounded by medical implements, skulls and pickled body parts and she is clearly right at home. Perhaps that's to be expected of someone who, given the opportunity, is more than happy to regale anyone and everyone with stories of Victorian surgery that would make even the hardiest stomach turn over once or twice.

Here's one of those tales now in fact. "I tried to tell this on public radio and they cut me off," she begins. So, fair warning gentle reader.

"There's a story about John Eric Erichsen [who was senior surgeon at University College Hospital in London in the 1840s]. A woman comes into the hospital and she's asphyxiating on all this blood and pus in her chest. And he goes to cut into her throat and all of this blood and pus comes spilling out and he lowers his mouth onto it and sucks all of this out."

She smiles as she sees the queasy look on my face. "Whenever I tell that to audiences they cringe."

Hmm, hardly a surprise, I'm thinking. But Fitzharris loves this stuff. The fast-talking, 35-year-old American medical historian has an eye for the ghoulish detail. She is also author of a book about Joseph Lister, the father of modern surgery, which is full of said details.

Fitzharris is in Edinburgh this evening to talk about it. Which is appropriate given that it is Lister's time in the Scottish capital and Glasgow that led him to the idea that infection was spread by germs, and in turn transforming surgical methods.

For Fitzharris, medicine is a useful gateway to understanding the past. "When you think about history sometimes it's hard to connect, but we've all been ill, some of us have faced our own mortality. And so there is a universality. What was it like if you had a toothache in the 18th century? Or what was it like if you broke your leg in the 19th century?"

Horrible, I suspect. As the opening chapters of Fitzharris's book, The Butchering Art gleefully and ghoulishly reveal, surgery back then was quite frankly something of a charnel house. If the operation didn't kill you, post-operative infections more than likely would.

Actually, reading The Butchering Art, it's quickly apparent that Victorian hospitals, indeed Victorian cities in general, were effectively machines designed to kill; disease rampaged throughout both.

"Operating theatres were filled to the rafters with hundreds of spectators who carried with them the dirt and grime of everyday life," Fitzharris explains of surgical practice in the early to mid-19th century. "That is what is so different when we think of how operations are done today and how sterile the environment, how controlled it is.

"Sometimes, it was so crowded that they would have to remove people from the actual floor of the operating theatre before they could proceed with the operation. And a lot of times the patient was fully awake as well. Imagine the terror of that situation."

Indeed, especially when you see the surgeon coming towards you wearing a gown covered in the dried blood and gore of previous surgeries.

Fitzharris had originally planned to write a book about another surgeon, one of Lister's predecessors, Robert Liston, because, she says, "he is so colourful and so much bigger than life. He's working in a pre-anaesthetic era and he's known as the fastest knife in the west."

"He's incredibly tall, he's 6ft 2in, and incredibly strong and he has these crazy mishaps in the operating theatre because he is so fast. In one of my favourite stories he accidentally takes off his assistant's finger and the assistant dies, the patient dies and as he's switching knives he cuts the coat of a spectator and the man dies of fright. So, it's jokingly referred to as the only operation with a 300 per cent mortality rate."

Liston opens the book. In 1846 he does the first operation – an amputation – in the UK where the patient is administered ether. It had only been used in the United States before. "We are going to try a Yankee dodge today, gentlemen, for making men insensible!" Liston announced to his audience of medical students and men and women off the streets.

The success of the operation led to the widespread adoption of ether. But that was not without its problems.

"We tend to think of that as being the moment when surgery is ushered into the modern era," explains Fitzharris. "But surgery becomes much more dangerous in that moment because we don't understand germs and the surgeon is more willing to pick up the knife, he's more willing to go deeper into the body. So, as a result, these operations become slow-moving executions."

In the audience crowded into the operating room in University College Hospital that December day was a 17-year-old Quaker called Joseph Lister. "I couldn't write the movie script better," Fitzharris beams.

In the early years of the 19th century scientists and doctors still believed that illness was spread in the air. Miasmas, it was believed, caused infection. It was Lister who would change that notion.

Born in 1827 he grew up in a Quaker family a few miles from London. His father Joseph was interested in science and fascinated with microscopes, a fascination he passed on to his son. After studying at University College London and then working (alongside Erichsen) in the University College Hospital, Lister moved to Edinburgh in 1853.

It was only meant to be for a short time, but he fell under the influence of his mentor Professor James Syme and eventually married Syme's daughter Agnes.

"Scotland was much more scientifically minded at the time," Fitzharris points out. "And more receptive to Lister's ideas when he came through with them."

Indeed, Edinburgh was a world leader in surgery at the time. That, in part, was the legacy of the resurrectionists a quarter of a century earlier.

There were other people working along similar lines as Lister when it came to ideas of infection. In Austria a physician called Ignaz Semmelweis surgeons coming from the dissection room to the wards were obliged to wash their hands in chlorinated water.

"People like Semmelweis or Florence Nightingale were using hygiene," Fitzharris explains, "but until you understood that germs were the cause there was no rhyme or reason as to how you applied the cleanliness rule. So, you really needed to understand how disease was spread before any real change could happen."

That's where Joseph Lister came in. Before Lister some pus in a wound was seen as a good thing, as necessary to aid healing. It was Lister, while working at Glasgow Royal Infirmary, who recognised that antiseptic treatment – he used carbolic acid – was required before, during and after surgery. "Lister takes the scientific principle and he applies it to medical practice," Fitzharris says.

On March 16, 1867, after two years of experimenting with carbolic acid at the infirmary, Lister published his findings in The Lancet under the title "On a New Method of Treating Compound Fracture, Abcess, etc., with Observations on the Conditions of Suppuration". In subsequent issues of the magazine he outlined his ideas, drawing on Louis Pasteur's research, that germs were the agents of infection.

In her book Fitzharris, who was originally from Chicago and now lives in London, tells Lister's story with novelistic detail and thriller bravura. The question we might ask her is why? Where did her interest in all things corporeal come from? Was she a Goth kid who didn't grow out of her love of Robert Smith and Anne Rice?

Not at all, she says. "My grandmother raised me because my parents divorced very early and my grandma never believed that children should be shielded from death, so I grew up around death. I went to a lot of funerals when family members died, and my grandma loves cemeteries. She's still alive and if I went home today she would get out her Audi Quatro and we'd head to the cemeteries because we love it.

"People think it's creepy, but I find cemeteries places of love where people spend a lot of money and time memorialising someone."

I can understand the attraction of cemeteries, I tell her. It's more the slippery, meaty reality of the body under the knife that I struggle with. Fitzharris gets that. "My mum's a nurse," she says. "I could never be a doctor myself. I couldn't treat patients. I have been offered to see an autopsy, but I passed up the opportunity."

Nor is she overly morbid, she says, though people have accused her of being so. "I am part of a group called The Order Of The Good Death, which is run by a woman called Caitlin Doughty in the US. She gathers artists and historians and funeral workers and all kinds of people in a conversation about how to open up dialogues about death and dying so it's not so scary.

"And from a medical historian's viewpoint I feel we have medicalised death so much. In the early 19th century people died at home, but that slowly starts to change when you get the introduction of morphine and cocaine in the later 19th century.

"And now the medical establishment really views death as failure. I would like to see doctors taught to open up more conversations with patients about what they want at the end of life and not necessarily see it as a failure. It's just a natural process."

She worries, too, about the current distrust of experts in our culture. The truth is, she says, we need more of them, not fewer. "What Lister was battling is not dissimilar to what we are battling in hospitals today. We have superbugs. We still have issues with large populations of sick people. Antibiotic resistance. Poverty is still an issue and as an American what are we going to be looking at in 50 years? Well, we are probably going to be looking at the fact that we don't have any kind of socialised medical system."

While she was working on The Butchering Art, Fitzharris would go to Lister's grave in West Hampstead and sit and write. "His grave is very plain. He gave up his Quakerism for his wife, but he still very much lived by the Quaker tenets. I would go there and sit and think about Lister and I would write his story."

She was going through a traumatic divorce at the time. "I suddenly found myself facing deportation. I had lived here for a long time, but I had broken my residence to follow my ex-husband to Canada for his job so when I came back I was just on a marriage visa."

When her husband decided he wanted a divorce her passport was confiscated and she wasn't allowed to work. She wrote the book proposal because there was nothing else she could do at the time. "I say this book is a love story to myself to prove that I could write and take care of myself."

There it is. Sitting here surrounded by death, Lindsey Fitzharris is telling me a tale of a life renewed.

The Butchering Art by Lindsey Fitzharris is published by Allen Lane, priced £16.99.