Note: When Dalrymple’s long-running BMJ column ended in 2012, he had a backlog of around 50 or 60 unpublished pieces, and he kindly gave them to us to post here at Skeptical Doctor. We are posting one each Wednesday to coincide with the schedule of his old BMJ column. We hope you enjoy them.

Publishers, in my experience, speak as if they had some special insight into the book market; but they are always surprised when a book sells either well or badly. The market is incalculable: who would have guessed that books with titles such as Does Anything Eat Wasps? Or Why Don’t Penguins’ Feet Freeze? would sell so well?

Yet there has long been a taste for arcane and miscellaneous knowledge. John Timbs (1801 – 1875), who once worked as a druggist, spent most of his life catering to the Victorian public’s thirst for facts, or supposed facts, compiling compendia about everything from ghosts to frescoes to electric telegraph cables. One of his most successful works was Things not Generally Known, my copy (1857) being a new edition that claimed to be one of the sixteen thousandth printed.

Among the things not generally known were some of medical interest, for example that epidemic cholera did not add to the overall mortality:

It appears that the total number of deaths in the cholera-year (1849), for all England and Wales, was 440,839; but in 1850 the number of deaths fell to 368,995, being not only 71,844 less than in the cholera-year, but even less than the number of deaths in the year preceding that of cholera, by as many as 30,838.

Averaging the number of deaths in the two pre-cholera years and that of the cholera year and the year following, we find “that no greater number of people died in those years because of the cholera intervening than if the cholera had not visited us.”

Is the moral of this that there was no need to panic, and that those victims of cholera should take consolation from the fact that they would have died anyway without it? Doctors, at any rate, could draw no such happy conclusion: Timbs mentions the fact that during “cholera visitations” between 12 and 20 per cent of “the medical men employed” died. True officers lead from the front.

Published only two years before On the Origin of Species by Means of Natural Selection, Timbs informed his readers that:

The new and brilliant science of geology attests that man was the last of created beings in this planet… she affords conclusive evidence that, as we are told in Scripture, he cannot have occupied the earth longer than six thousand years.

But as for individual humans, their time is short:

The average of Human Life is about 33 years. One quarter die previous to the age of seven years; one half before reaching 17. To every hundred persons, only six reach the age of sixty-five.

For the enlightenment of those lucky six, Timbs turns his attention to the important question of human hair turning grey, and tells the following story of a doctor:

A medical man in London, less than twenty years ago, under the fear of bankruptcy, had his dark hair so changed in the same period that his friends failed to recognise him; but the colour in this instance returned, as his worldly prospects revived.

There is hope for me yet, then; unlike Lady Harbury’s hair, that turned quite gold from grief, mine might (if my investments do well) turn quite brown from prosperity. The colour of my hair depends, then, on the outcome of the crisis.