Anyone who has baked and enjoyed cakes knows that satisfying smell that comes from the oven, the resistance of a knife against the cake crust, the way those tiny crumbs tumble platewards as you sink your dessert fork into the freshly cut slice... Unfortunately, everyone also knows that wrong proportions, dodgy ingredients, wonky ovens and many other, more elusive parts of baking can result in brick-like buns, smelly situations and, inevitably, tears. An even more embarrassing scenario when you're having guests over. I am speaking from the experience of someone who has sworn at many a malfunctioning oven in a host of rental hovels. But I soldier on in the knowledge that I am not the only one suffering from oven envy. (Incidentally, some people who have had children can take the image of the ruined baked good as a metaphor for buns of the other kind - but I won't dwell too much on that.)
From J. J. Becher, Physica subterranea (1st ed. 1669, here 1703)
Image from the Chemical Heritage Foundation
Alchemists had their own ideas about ovens and reproduction. Curiously, not about cakes, as far as I know. Anyway, many metaphorical images that are ubiquitous in alchemy involve the conjunction of male and female bodies resulting in the birth of a child (read: the mixing of two different components, who join to become a third); and the gestation of matter in a hot environment. Sometimes, the father will eat the child (the third substance is mixed with one of its original components); in other scenarios, they both go into a sauna (moist heat, think baker's oven).
If you think about it, this way of thinking about chemical processes makes a lot of sense: it allows for the distinction between of similar and different substances, the definition of their origins, and for the development of a theory of how these metals, minerals and other materials can, and cannot, be used. And all with the help of a (forgive the pun) familiar picture. This is particularly useful when things go wrong in the alchemical workshop. For example, if mixed ingredients refuse to mingle, they might both be 'male'. If the child they produce is not sweet but a rather frightening brat, they were not compatible. If it comes out resembling charcoal, the oven/womb was too hot. What you end up with is a network of materials and procedures that will produce reliable results. And to be honest, even if this alchemical shorthand is not an exact science according to today's standards, it is much more attractive than a hexagonal molecular structure.
Molecular structure of caffeine
found on Wikipedia
On that note, I'll end this short and sweet post, because I've got a cake in a rather crappy oven. I fear it may come out charred on one side and uncooked on the other. But I shall love it anyway.