Mixing chemical and conjuring magic

The school scientific society occupied a large part of my extra-curricular school activity.  It met on Saturday mornings, given that the school had ceased to hold classes then.  Under the tutelage of two inspirational teachers, Mr Gregory and Mr Siddle, we met in the school chemistry lab and performed experiments.  We made rockets, exploding glass beads and we welded metal with the thermite process using powdered aluminium and iron oxide.

The teachers encouraged us to appear in front of the class occasionally to make a presentation, no small thing for 14 year-olds.  I chose to deliver a display of chemical magic, selecting some showy reactions that produced dramatic results. I performed stunts like blowing lycopodium powder through a tube across a Bunsen burner, sending a sheet of flame shooting out.  It was part showmanship, part science.  I had liquids run through a range of colours, and had crystals growing in beakers like jungle undergrowth.

Most of the displays were chemical, but I was an amateur conjurer, so I mixed in some sleight of hand magic as well.  A volunteer held a playing card wrapped in a cloth over a flask of water to which a few drops of "my special ink" had been added.  He pushed the card into the water at my behest, and whipped the cloth away.  To his puzzlement and that of the watching class, the card had dissolved.  When I had given him the card wrapped in the cloth, I had secretly substituted a piece of light blue acetate paper cut to the size of a playing card, while palming the real card.  In the light blue water it could not be seen.  Hey presto, magic.