John Cox, of Kings High School, asks :-

What is Condy's crystals and where did it get its name from?

Alan Happer, a chemist at the University of Canterbury, responded

`Condy's crystals' is an old name for potassium permanganate.

Manganese occurs naturally in the form of pyrolusite. This mineral, known in ancient times, was considered by Pliny to be the female form of lodestone, the magnetic ore of iron on the basis that it looked like it, but was not magnetic. Originally it was called magnesia. It was traditionally added in small amounts to glass, because it removed traces of yellow or green colour, giving a much-prized transparent product.

In 1659 a German, J.R. Glauber, fused a mixture of pyrolusite and fixed alkali (potassium carbonate) and obtained a material that, when dissolved in water, gave a green solution which slowly changed colour first to blue, then violet, and finally red. The chemistry involved is quite complex and was not completely understood until relatively recently.

Enter Henry Bollmann Condy, 200 years later. He was a Londoner whose mother inherited a chemical factory from a Dr Bollmann, a Hungarian chemist. Condy trained as a chemist and took over the business. He apparently had an interest in disinfectants, marketing products such as `ozone water'. He found that when he fused pyrolusite with caustic soda and dissolved the product in water it gave a solution that had good disinfectant properties. He patented this solution, and marketed it as `Condy's Fluid'.

The problem was that the solution, although effective, was not very stable. This difficulty was overcome by using caustic potash instead of caustic soda. This gave a more stable material, which had the added advantage of being easily converted to the equally effective potassium permanganate. The latter had a further advantage over sodium permanganate - being much less soluble in water, it was easier to isolate from the solution as crystals (Condy's crystals). Because potassium permanganate was so easy to make, Condy was subsequently forced to spend considerable time in litigation in order to stop competitors from marketing similar products as `Condy's Fluid' or `Condy's Crystals'. Solutions of Condy's crystals, like tincture of iodine, still find some use as an antiseptic, but these days better products are available.