The little finger is the finger of Mercury, named for the Mount of Mercury below it, and the reading follows the planet in both of its faces. Favourably it is speech, quickness, dealing, aptitude for commerce and for science, the gift of putting a thing well. Unfavourably the same qualities turn into cunning, evasion and a talent for deception, which is the mythological Mercury exactly, messenger and thief in one figure. A long little finger is read for eloquence and shrewdness, a short one for difficulty in saying what is meant, a crooked one, in the harsher manuals, for dishonesty.
The Mercurial district of the hand extends below the finger as well. The health line, called the Mercury line and in older texts the hepatica, or liver line, rises from this region, and its two extra names show the scheme drawing on astrology and on humoral medicine at once rather than on anything found in the palm itself.
This is the smallest digit and the tradition gives it the largest share of social meaning, which is characteristic of the system. Chiromancy distributes the whole of a character across the hand and then finds each part confirmed by what it had already assigned there. The associations are traditional and interpretive, and controlled tests of the practice have not found them.