Either together or successively he held the offices of inspector of mines, professor at the School of Mines and at the Polytechnic School, assayer of gold and silver articles, professor of chemistry in the College de France and at the Jardin des Plantes, member of the Council of Industry and Commerce, commissioner on the pharmacy laws, and finally professor of chemistry to the Medical Faculty, to which he succeeded on Fourcroy's death in 1809.
William Speer was supervisor and chief assayer of spirits in the port of Dublin.
He had been a member of the consultative committee on arts and manufactures since 1805; he was attached to the "administration des poudres et salpetres" in 1818, and in 1829 he received the lucrative post of assayer to the mint.
To simplify calculation and to enable the assayer to use the metric system of weights employed in all chemical calculations, the "assay ton" ("A.T."
Among the more important officers appointed by the governor are the superintendent of public instruction, the commissioner of agriculture, statistics and mines, an assayer, state entomologist, and officers of the penitentiary.