  We study dyonic instantons in (4+1) dimensional Yang-Mills theory. Especially
we consider the most general two instanton solution given by the
Jackiw-Nohl-Rebbi ansatz and find its dyonic version. By exploring the zeros of
the Higgs field, we rederive the porism structure of triangles in this solution
and also find the magnetic monopole string loop. This leads to the
identification of dyonic instanton with the supertube inserted between D4
branes.
