White was born in Edinburgh on 29 April 1817. He became acquainted with John Edward Gray, Keeper of Zoology at the British Museum. At the age of eighteen, White obtained a post in the Museum in the Zoology Department. In 1841 he was given the task of identifying and publishing the spiders collected by Charles Darwin on the Voyage of the Beagle and "preserved in spirits of wine, as spiders should always be if possible". This work was published as "Description of new or little known Arachnida".