  In this paper we study the rank one discrete valuations of $k((X_1,...
,X_n))$ whose center in $k\lcor\X\rcor$ is the maximal ideal $(\X)$. In
sections 2 to 6 we give a construction of a system of parametric equations
describing such valuations. This amounts to finding a parameter and a field of
coefficients. We devote section 2 to finding an element of value 1, that is, a
parameter. The field of coefficients is the residue field of the valuation, and
it is given in section 5.
  The constructions given in these sections are not effective in the general
case, because we need either to use the Zorn's lemma or to know explicitly a
section $\sigma$ of the natural homomorphism $R_v\to\d$ between the ring and
the residue field of the valuation $v$.
  However, as a consequence of this construction, in section 7, we prove that
$k((\X))$ can be embedded into a field $L((\Y))$, where the {\em ``extended
valuation'' is as close as possible to the usual order function}.
