Gibbs ([1889, p. 140](https://archive.org/stream/americanjourna3371889newh#page/140)):
$$
\frac{d\,\log\mathrm V}{d\,\log p} = - \frac{d\,\log n}{d\,\log\lambda}.
$$Legendre ([1826, p. 466](https://archive.org/stream/bub_gb_c4M_AAAAcAAJ#page/n491)):
$$
\frac{d\,l\,\Gamma a}{da} +
\frac{d\,l\,\Gamma(\frac12+ a)}{d(\frac12+ a)} - 
\frac{2d\,l\,\Gamma(2a)}{d(2a)} =
-2l\,2.
$$
L'Huilier ([1795, p. 96](https://archive.org/stream/principiorumcal00lhugoog#page/n136)):
$$
\frac{d.a^{\mathrm z}}{d.\log.z}= A.a^{\mathrm z}.
$$