When the Jorvik Centre - a Viking "experience" - opened in York, one of the things that children liked about it was that you could smell the privies.
The same thinking lies behind this series. It not only dwells - in stomach-churning detail - on maggots, gazelle dung, pigs' bladders, cheesy feet and nasty boils, but actually provides some scratch-and-sniff patches.
In Vile Vikings, for example, a spread of illustrations and captions about life in a Viking town reads, "Bjorn is enjoying a little privy privacy" and adds "Scratch and sniff for a peaceful whiff!" To object to this approach is to risk being accused of bringing po-faced adult sensibilities to bear on something that children will enjoy.
For me, though, the books are interesting enough without all the revelling in muck. Given their size, (32 illustrated pages) they are good on the detail of everyday life, and they manage to cover other topics too - Greek Grime, for example, is good on the Olympic Games, on the legends and on the wars with neighbouring city states. There seems scant reason to trivialise the content - and risk patronising the readership - with smelly patches and such dreadful chapter headings as 'Meaty Mummies', 'Odorous Ordeals' and 'Oily Olympics'.