Experiments with fire proofing cloth.
Having been told the commonest form of death for young maidens in Tudor times was their kirtles catching alight as they stirred pottage on an open fire, I got quite worried and decided to investigate.
I held various pieces of fabric over a candle flame and this is what happened......
Cotton took 2 seconds to catch alight and burned with a vengeance.
Linen to 3 seconds to flare up.
Wool lit after 19 seconds but went out when moved away from the candle. It went black and crispy.
A thick, well washed and dyed, woollen, army blanket would not burn. It went black slowly - 2 minutes to cover 2 square inches - then crumpled to ash.
I squirted fire proofer onto linen and starched linen. (You couldn't tell when they were dry.)(I also wore a strip around my wrist for a day looking for an allergic reaction, but nothing happened.) It took 20 seconds before the pieces of linen started to singe. 3 minutes later 1 square inch on each was black but intact. They did rip when I tugged on them.
One of my friends told me of borax. I put 1 teaspoon of borax into a sandwichbox of water (trying to mimic one handful of borax in a bucketful of water) and I dunked some linen in it. When it was dry I wafted it over the flame. In 2 seconds it caught alight, but the flame went out and the linen smouldered with a red glow, charring to black until it had advanced 2 inches,
when it put itself out. This was so weird that I did it again and the same thing happened.
I have since found a solution of alum suggested as a fire retardant in a 1920's household encyclopaedia but haven't tried it yet.
Annie the pedlar