How would a 17th-century woman know if she’s pregnant? Why, by the following signs of course: “pains in the head, vertigo, and dimness of the eyes…the eyes themselves swell, and become of a dull or dark colour”.

Aristotle’s Masterpiece was the most popular manual about sex, pregnancy and childbirth from its first appearance in 1684 through hundreds of editions up to the late 19th century. The manual offers advice on everything from “the use and actions of the genitals” to “monstrous births, and the reasons thereof”.

This is a book for the common people that would’ve been cheaply printed, sold under the table and hidden under the mattress at home. With its advice for both men and women, it would’ve been furtively rifled through as often as we use Google (rightly or wrongly) to decipher our medical problems nowadays.

Aristotle’s Compleat Master Piece. The twenty-seventh edition. [London]: printed and sold by the booksellers, 1759

In case you hadn’t already guessed, Aristotle’s Masterpiece is neither by Aristotle or, indeed, a masterpiece. Nicolas Culpeper had already written his Directory for Midwives in 1651 and other writers and booksellers sought to emulate its resounding success. Aristotle was a long-established pseudonym used when printing works about reproduction. The text itself is a peculiar mash-up of early 17th-century medical works and popular old wives’ tales about sex and reproduction passed down through generations.

For instance, is it a boy or a girl? For this, the book says, “male children lie always on the [right] side of the womb” and girls on the left. But if you wanted to be certain, cast a drop of milk into a basin of water. If the milk drop sinks to the bottom intact, it’s a girl. If it spreads and disperses on the surface of the water, it’s a boy. With sage advice like this, it’s hardly surprising that copies of The Masterpiece were used until they literally wore out. This means that comparatively few survive today, with the British Library being lucky to hold about 30 different early editions.

To us, Aristotle’s Masterpiece is a delightfully eccentric insight into 17th-century sexual and reproductive lore, sometimes recognisable as the precursor to modern science and sometimes decidedly not.

Aristotle’s Compleat Master Piece. The twenty-seventh edition. [London]: printed and sold by the booksellers, 1759

This manual devotes a lot of time to describing monsters, for example. These “monstrous births” are variously attributed to “maternal imagination, witchcraft, human-animal copulation or a disorder of the womb”. The crude curious woodcuts, instrumental to the manual’s appeal, feature a child with its eyes where its mouth should’ve been, a naked woman covered in hair and conjoined twins amongst others.

Aristotle’s Compleat Master Piece. The 27th edition. [London]: printed and sold by the booksellers, 1759

Elsewhere there are largely sensible instructions for midwives. The basic anatomical descriptions and the large, fold out diagram of the position of a baby in the womb also occupy more familiar territory for modern readers.

Aristotle’s Compleat Master Piece. The twenty-seventh edition. [London]: printed and sold by the booksellers, 1759

But home remedies that feature dog’s grease or even dragon’s blood soon confuse matters again. As does the insistence that bleeding a woman, a somewhat primitive practice, is advised if she’s having difficulty during childbirth and that, during pregnancy, a woman must ensure that her home is not, for some inexplicable reason, “infected with frogs”. Ribbet.

This article first appeared on British Library’s Untold Lives blog.