They are normally used in alternative medicine rather than schools - but pupils are set to use scented oils to help them learn quadratic equations and French verbs.

So-called “memory oils”, with their pungent aromas of lavender, grapefruit and mint, will aid students’ recall of key facts in exams, it has been claimed.

Sydenham High School - a private girls’ school with fees of pound;12,000 a year - is planning to distribute three different scented oils to Year 9 special educational needs (SEN) students along with revision guides to help them prepare for exams in January.

It will use grapefruit scents for maths, lavender for French and spearmint for history. Students will be encouraged to use the oils while studying and then again before exams.

Anthony Padgett, the owner of Memory Oils, has designed 19 different scents for use with different subjects.

He claims that using a handkerchief soaked in grapefruit oil helped his daughter, who suffers from dyslexia, perform better in her exams.

“She was predicted Bs and Cs in her GCSEs,” he said. “But she came out with A*, As and Bs. She puts it down to the oils.”

According to Mr Padgett’s website,“Your sense of smell quickly associates the fragrance with the subject, so you can then boost your recall by using the scent before exams”.

Fintan O’Regan, an SEN and behaviour consultant for the Specialist Schools and Academies Trust, has backed the use of smells as a way of helping pupils learn.

“I work with an open mind to new techniques in learning and behaviour and this sounds like an interesting concept to me,” he said.

“It’s true that certain smells can remind you of past events, so to use scents while studying a topic is another way of stimulating your brain.

“Some people find these things annoying and some find them quirky, but anything you can do to improve mood and overall performance has good mileage.

“The more we talk about multi-sensory teaching, visual aids and auditory learning, the more teaching through smell should also be used.”

In the US, Dr Rachel Herz, an expert on the psychology of smell based at Brown University, Rhode Island, has performed experiments which showed that the ability of children to solve puzzles was improved with the use of certain aromas.

Some Japanese businesses have also experimented with pumping smells into their offices to reduce stress and errors.

However, Roger Pope, head of Kingsbridge Community College in Devon, urged caution. “Other than the fact that the exam hall will smell like a perfumery, I think it’s nonsense,” he said.

“Memories can be triggered by sensory experiences but the whole idea is highly suspect.

“To say that you will remember your calculations by smelling grapefruit is contrived.”

Aroma academy: Making scents of brain boosters

In his book Using Brain Power in the Classroom: Five Steps to Accelerate Learning, author Steve Garnett suggests a number of smells that can be used to improve pupil performance:

- Reduce stress - spiced apple, rose and chamomile.

- Reduce anxiety - vanilla, neroli and lavender.

- Relax - basil, cinnamon and citrus flowers.

- Energise - peppermint, thyme and rosemary.

- Relieve tiredness - woody scents, cedar and cypress.

• Original headline: ‘Memory oils’ to splash private pupils in sweet smell of exam success