The article discusses the historical prevalence of goitre and cretinism in Switzerland, which was caused by iodine deficiency due to the country's geology. In the early 20th century, a Swiss doctor named Heinrich Hunziker proposed that iodine deficiency was the cause of these conditions, and advocated for the use of iodized salt as a solution. Despite initial skepticism, Hunziker's theory was eventually proven correct, and the use of iodized salt has since become a widespread public health measure. The article highlights the challenges of discovering the cause of a disease and the importance of perseverance in the face of skepticism.