THE INCOMBUSTIBLE THREAD.
Wind some linen thread tightly round a smooth pebble, and secure the end; then, if you expose it to the flame of a lamp or candle, the thread will not burn; for the caloric (or heat) traverses the thread, without remaining in it, and attacks the stone. The same sort of trick may be performed with a poker, round which is evenly pasted a sheet of paper. You can poke the fire with it without burning the paper.