I then started, as always, the way I write, is to start at the beginning, to go on until I come to the end and then stop, as Lewis Carroll said. And that’s the way I always write, if I’m writing a lecture or a textbook or a monograph on something, a thesis when I was an undergraduate, graduate student. I have a plan of course – I knew the sequence of the elements – I start at the beginning and I just keep on writing.

Some chapters are longer than others, I have to keep a balance of course, but that then brings me on to another theme, which makes the book perhaps unusual. And that is, as I briefly mentioned, the chemicals that we’re talking about may be unique because they’re theoretically important or because they’re just beautiful or surprising or they may be useful.

So I was able to weave in, and I had what I call panels, coloured bits, inserts, which were the uses of the elements perhaps, or where they came from, or side effects, an aside, like the Oklo phenomenon that we were talking about, that would be one such panel, which is not the main stream but is an interesting thing.

In fact my secretary, who was typing this at one stage, working back evenings and so forth, once said, they’re the most interesting part of the book, I don’t understand the other rubbish, but I like reading this. And that was from a non-scientist.