On the death of his mother the child was removed by his father to Scotland, where he was educated and taught the use of the finger alphabet, by means of which people are enabled to hold discourse with each other, without moving the lips or tongue.

This alphabet was originally invented in Scotland, and at the present day is much in use there, not only amongst dumb people, but many others, who employ it as a silent means of communication.
Nothing is more usual than to see passengers in a common conveyance in Scotland discoursing with their fingers.

Duncan at an early period gave indications of possessing the second sight.

After various adventures he came to London, where for many years he practised as a fortune-teller, pretending to answer all questions, whether relating to the past or the future, by means of the second sight.

There can be no doubt that this man was to a certain extent an impostor; no person exists having a thorough knowledge either of the past or future by means of the second sight, which only visits particular people by fits and starts, and which is quite independent of individual will; but it is equally certain that he disclosed things which no person could have been acquainted with without visitations of the second sight.