Making materials we can use

Yasmin Jayathirtha

I hope you enjoyed the special issue on chemistry. There were a lot of articles that described the modern chemicals and processes. Many authors wrote about their enjoyment of the subject and what hooked them to it – a magical colour change or an explanation of a phenomenon. I like the subject and I date my interest to the time, when, after a class on acids and bases, I washed a haldi stain off my white uniform blouse and recognized the colour change as an indicator colour change. This interest has continued and the fact that I can explain many reactions in daily life is a large part of the fun.

I have often wondered how people long ago made and used new materials. What did they observe? How did they recognize uses, say, of medicinal plants? When and how were the chemicals of general use made? Consider personal hygiene – cleaning agents have been used for a long time. They have been sourced from nature; shikkakai, reetha, neem twigs, hibiscus flowers, multani mitti… Every culture has similar cleaning agents. What observations