John Tyndall worked as a surveyor before travelling to Marburg to study science under Robert Bunsen. He taught at Queenwood College before being appointed a Professor at the Royal Institution (Ri). At the Ri he undertook important work on diamagnetism, radiant heat and spontaneous generation. He also worked on glaciers and became a keen mountaineer, in 1861 he was the first person to climb the Weisshorn. Tyndall wrote many popular scientific articles and books and was outspoken about his views about scientific naturalism – the view that things in nature are best explained without invoking theological explanations. Hel died due to an accidental overdose of medication administered by his wife Louisa. This painting is a copy of an original portrait by J.