The history of disease contributes to a better understanding of the growth of ideas in medicine. The colonial period was marked by a rapid increase in the variety of diseases that were known to European practitioners. We have studied the diary of Dr Charles Smith who worked in Bangalore in the nineteenth century. We feel that some of his descriptions tally with later accounts of cysticercosis. He also comments on a wide range of behavioural symptoms, and attempts to correlate neuropathological observations to these. This neuropsychiatric perspective was prominent in the nineteenth century. Infective causes of psychiatric disorders are once again considered important; this account highlights the fact that similar ideas were prevalent in British India, even 150 years ago. In addition, Dr Smith's comments describe the social mileu of 'western' medicine in India in the early colonial period.