  It is shown that harmonic functions from a simply connected domain in R^3 to
R^3 cannot always be expressed as a sum of a monogenic (hyperholomorphic)
function and an antimonogenic function, in contrast to the situation for
complex numbers or quaternions. Harmonic functions orthogonal in L_2 to all
such sums are termed "contragenic" and their properties are studied. A "Bergman
kernel" and is derived, whose corresponding operator vanishes precisely on the
contragenic functions. A graded orthonormal basis for the contragenic function
in the ball B^3 is given.
