An improvement of a lemma from Gauss’s first proof of quadratic reciprocity

An upper estimate is given for the least prime $q$ such that $(d/q)=1$ and $(p/q)=-1$, where $d\not =0$ is a given integer and $p$ is a given prime satisfying $p\equiv 1\ ({\rm mod}\ 8)$ and $(d/p)=1$.