Data artist Nicholas Rougeux created a gorgeous collage of over 2,000 early 19th-century illustrations by James Sowerby. The public domain images were organized from over 700 color plates by color as a beautiful poster, but Rougeux also created a website where the work can be explored as a learning tool.
For instance, here is his illustration of copper peroxide:
Aug. 1. 1808. Publish'd by Ja.s Sowerby London.
British MineralogyTAB. CCLXXIXCUPRUM hyperoxygenizatum
Peroxide or rather Hydrate of Copper
The specimen here figured was brought from Dalehead-mine, in Cumberland, and is in the possession of W.E. Sheffield, Esq., who, with the utmost generosity, has offered to lend his best specimens for this public use.
Here's the poster for those interested.
Image: Nicholas Rougeux / c82.net