Cesspit enviro in the 100 Minories Lab

Matt Law

May 16, 2016


MNOX6424

The sun has been shining, the days have been lengthening and the sap has been rising. Filled with the wonders of the rebirth of nature, thoughts in the L – P enviro lab naturally turn to cesspits…  Cess pit samples have entered the flotation tank from 100 Minories, as well as other recent sites, St Olavs (SOL 13) and Prescot Street (PRE 14).

Fig (Ficus carica L.) seed from 100 Minories

Fig (Ficus carica L.) seed from 100 Minories

One of the surest signs of lovely nightsoil in a deposit are the seeds of edible plants – elder (Sambucus nigra) and blackberry (Rubus fruticosa) are particularly common, as are grapes (Vitis vinifera) and lots and lots of fig (Ficus carica) seeds. These are a recurrent feature of samples at all three sites. Figs are of some interest, as they can only be fertilised by a wasp that lives on continental Europe, which means that figs containing seeds large enough to preserve are imported rather than homegrown.

 

Turtle soup anyone?

 

Turtle cranial bones from 100 Minories, with added value finger photobomb.

Turtle cranial bones from 100 Minories, with added value finger photobomb.

One of the true wonders of 100 Minories was a small sample alluringly described as ‘fill of a chamber pot’. Sure enough, figs and all that were in there, but so was a selection of much larger bones (surely not passed by a human). These appear to be various bits of the skull of a turtle, possible green turtle (Chelonia mydas). Turtles enjoyed (ok, they probably didn’t actually enjoy it all that much) some popularity in late 18th to late 19th century London as ingredients of turtle soup. The 1753 issue of Gentleman’s Magazine reports the cooking of a turtle weighing 350 lb at the King’s Arms on Pall Mall – this required the door of the oven being removed to fit the turtle inside. Turtles were brought to London from the Caribbean and also Ascension Island. They were expensive, so green turtle soup was only really enjoyed by the wealthier classes. A cheaper alternative, mock turtle soup, was made using a calf’s head. The Minories bones are the real deal however.

 

A Mediterranean mystery

 

A rustic dove shell (Columbella rustica)

A rustic dove shell (Columbella rustica)

Speaking of exotics from 100 Minories, last week I came across a shell I didn’t recognise from the soakaway at the back of one of the houses (from which I was generously gifted 21 buckets of material). A visit to the collections of the National Museum of Wales in Cardiff revealed that this was a rustic dove shell (Columbella rustica), a small carnivorous marine snail from the Mediterranean. It isn’t food, and it isn’t pierced in any way that would suggest jewellery, so what is it doing among the faeces and food waste of a London household? My best guess is that, as it is quite a pretty shell (you’ll have to trust me on this, they look a bit nicer when they haven’t been rubbing shoulders with excrement for over a century), it may have been picked up as a curio on a Mediterranean beach trip, and been lost in the house, entering the soakaway among floor sweepings (there are also a number of tiny beads and copper alloy pins that may be from sweepings).

 

Oh good grief why are you telling me this?

 

Fish tapeworm (Diphyllobothrium latum) eggs. The eggs are roughly 50µm each.

Fish tapeworm (Diphyllobothrium latum) eggs. The eggs are roughly 50µm each.

One of the real delights of the Minories and Prescot material has been looking at parasite eggs from the cesspits. Parasitic worms from Minories so far have included whipworm (Trichuris trichiura) and pork or beef tapeworm (Taenia sp.), while Prescot has yielded giant roundworm (Ascaris lumbricoides). Roundworm and whipworm infections result from poor sanitation, and beef or pork tapeworm from undercooked meat. The biggest surprise for me though was that so far the most prevalent at both sites is the broad fish tapeworm Diphyllobothrium latum. This friendly creature, which can grow to 10 metres long in the small intestine of its host (i.e, a person) and live up to 20 years, is acquired from eating undercooked freshwater fish. If I can pass on one piece of advice to you, it’s that you should never ever attempt an image search of any of these creatures, and especially not Ascaris.