@edgarblythe,
paints in those days (with the exception of the brilliant blues, which were made of a pigment which was like a ground blue glass called lazurite and maroon garnet color and carbon black. All other colors were based on **** like cadmium, copper carbonate, lead salts, chrome salts and oxyhydroxides, Prussic blue Iron, and even uranium salts and mercury salts for vermillion and deep red, as well as the leafy greens of arsenic sulfide salts . The fastness of these colors were barely able to endure for a generation. Like all the copper blues (azurite) would quickly transform to green (malachite). Thats why most family portraits were hung in dark areas and viewed in passing by candle light.
Environmentally induced dementias were common in many trades, painting was just one. People who did wall decorations were generally dead by their thirties.
I started my interest in environmental chemistry doing research on the toxicity of ancient artist pigments . Many artists were considered "nutty" , and many were honestly nuts but more were probably suffering from heavy metal dosing.
