Mystery object. Not a button, as there is no means of fastening it. Possibly a piece from a game? it’s about an inch (2cm) across.
Piece of Jurassic Park plastic. Presumably from some kind of toy or game.
Scaffold ringbolts. Made by Hilti, a Liechtenstein-based building products company. These ones, which are eight inches long and very sturdy, no longer appear to be on the market.
Engine part. Looks fairly monstrous.
Pro Plus caffeine tablets. These are supposed to increase alertness and are apparently much used by students. It’s a pity the owner of this lot wasn’t alert enough to avoid losing them in the River Thames.
152. This is on a metal plate - no idea what it came from, though. Wikipedia helpfully tells us that 152 ‘is the natural number following 151 and preceding 153’.
Milk bottles. One pint, two half pints. These must have been in the mud for some time and had to be dug out.