Young men from eighteen to twenty occasionally become gray; and according to Rayer, paroxysms of rage, unexpected and unwelcome news, diseases of the scalp such as favus, wounds of the head, habitual headache, over-indulgence of the sexual appetite, mercurial courses too frequently repeated, too great anxiety, etc., have been known to blanch the hair prematurely.
The well-accepted fact of the sudden changing of the color of the hair from violent emotions or other causes has always excited great interest, and many ingenious explanations have been devised to account for it.

There is a record in the time of Charles V of a young man who was committed to prison in 1546 for seducing his girl companion, and while there was in great fear and grief, expecting a death-sentence from the Emperor the next day.

When brought before his judge, his face was wan and pale and his hair and beard gray, the change having taken place in the night.

His beard was filthy with drivel, and the Emperor, moved by his pitiful condition, pardoned him.

There was a clergyman of Nottingham whose daughter at the age of thirteen experienced a change from jet-blackness of the hair to white in a single night, but this was confined to a spot on the back of the head 1 1/2 inches in length.