Inside the hearing room industry representatives illustrated their presentation with slides showing cans of lighter fluid, different sizes of barbecue grills and clumps of charcoal briquettes.

Other photos show huge clumps of snowdrops mingling with a heady assortment of hellebores, crocuses, iris and aconite in a woods full of birch trees.

Nerve cell bodies stained with basophilic dyes show numerous microscopic clumps of Nissl substance (named after German psychiatrist and neuropathologist Franz Nissl, 1860-1919), which consists of rough endoplasmic reticulum and associated ribosomal RNA.

A couple of bowls showed hairy dark green clumps that floated beneath the surface like submerged sea beasts, dark and sinister.

They showed clumps of dead flies, close-ups of other insects, microscopic images of bacteria and smudges identified as bluish impurities, among other things.