Let’s turn to your first book, Jon Camden Hotten’s A Dictionary of Modern Slang, Cant and Vulgar Words. This was first published in 1859 – why is it still relevant today?

Hotten is the first slang lexicographer to come up with a considered treatment of the history of slang and indeed of cant, or criminal slang. He also offers a history of back slang and rhyming slang. His is a substantial bibliography, which no one had done before him. No-one had ever written about slang in the way that Hotten did. His definition of slang is one of the best there is:

“Slang represents that evanescent, vulgar language, ever changing with fashion and taste, … spoken by persons in every grade of life, rich and poor, honest and dishonest … Slang is indulged in from a desire to appear familiar with life, gaiety, town-humour and with the transient nick names and street jokes of the day … Slang is the language of street humour, of fast, high and low life … Slang is as old as speech and the congregating together of people in cities. It is the result of crowding, and excitement, and artificial life. It is often full of the most pungent satire, and is always to the point. Without point Slang has no raison d’etre.”

If you want to find the starting point at which to look at slang, rhyming slang, back slang and a variety of other sub-sets, plus a very good assessment of what was available in terms of slang lexicography in 1859, then Hotten’s your man.

Hotten was a colourful character. What more can you tell us about him?

He had a shop on Piccadilly where the Ritz Hotel now stands. He was a publisher. He was a bit of a plagiarist, or more of a pirate really. He published authors like Mark Twain. Of course, there was no copyright then. There was also his “flower garden”, which was pornography. Some say the pornography kept his business going. Others disagree. We don’t really know the answer. In all he produced about a million and a half physical books in the last 10 years of his publishing life, which ended in 1873. His firm was bought by his assistant Andrew Chatto and eventually became the firm Chatto & Windus, which exists today.

There is some mystery surrounding his cause of death. Some said brain fever, others claimed a surfeit of pork chops.

One person came up with the line, after it was suggested that he died from a surfeit of pork chops, that this was proof that cannibalism was not a good idea. The joke being that he was pig and ended up eating himself. Others were more generous, saying he was a workaholic, helped authors and never made much money.

Moving on to your second book, Eric Partridge’s Slang To-day and Yesterday which was published in 1933.

Eric Partridge was the leading English language slang lexicographer of the 20th century. His Dictionary of Slang and Unconventional English appeared in 1937 and editions continued to appear until the posthumous edition of 1984.

Partridge cut his lexicographical teeth in 1933, when he published this history of slang, Slang To-Day and Yesterday. This book is not just his own first essay into the subject, but also the first attempt at slang lexicology since John Camden Hotten's comprehensive history and explanation of slang appeared in 1859.

Partridge begins by offering a discussion of the linguistic phenomenon that is slang. Then he puts forward his own opinion on the etymology of the word “slang”, and suggests what constitutes a slang word – he gives 17 qualifications – as opposed to a colloquial or standard English one. He follows these theoretical chapters by a succession of chronological ones, in which he lays out both the major slang lexicographers from the 16th century onwards and the authors who up until the date of his writing had made the greatest contribution to the recording of slang vocabulary.

For me, of course, Partridge is the great mentor. I may not agree with everything he did, and as his successor I have naturally tried to improve on his foundations. But without his example I would have never even considered that slang was something to which I could enthusiastically devote my professional life.