We introduce a calculus of the Lie algebra valued functions present in
Tseytlin's proposal for the nonabelian DBI action, and apply it to show that
the recently found dyonic instanton is a solution of the full nonabelian DBI
action. The geometry of this solution exhibits a new effect of ``blowing-up''
of the brane, which was not present in the case of the brane realisation of
monopoles. We interpret this solution as the superposition of the D0 brane and
fundamental string F1 which connects two separated D4 branes. Both F1 and D0
are delocalised in the ``blown-up'' region between two separated D4 branes.Comment: 14 pages, 3 figures; v2: minor changes and added reference
