=Panel No. 9--Orange Mineral.= In excellent condition, showing a good firm surface with no checking or corrosion apparent. Shortly after exposure the film became covered with a white coating of carbonate of lead, which indicates action of the red lead with the carbonic acid of the atmosphere. Removal of this white coating with water discloses the brilliant color of the unaffected portion of the red lead. =Panel No. 10--Red Lead.= In same condition as Panel No. 9. =Panel No. 12--Bright Red Iron Oxide.= In general good condition. Film intact and unfading in color. =Panel No. 14--Venetian Red.= Similar to Panel No. 12, but slight corrosion apparent beneath, in localized spots, and film showing slight wart-like formations. =Panel No. 15--Prince's Metallic Brown.= Similar to Panel No. 14. =Panel No. 16--Natural Graphite.= Deeply pitted in spots, showing bulbous eruptions, indicating the stimulative nature of this pigment. =Panel No. 17--Artificial Graphite.= In same condition as Panel No. 16. =Panel No. 19--Lampblack and Barytes.= Although the film seems to be intact, there are apparent abrasions of the surface showing stimulative corrosion effects of a pronounced nature. =Panel No. 21--Carbon Black and Barytes.= In same condition as Panel No. 19. [Illustration: Corrosion Pits on Graphite Panel] [Illustration: Rust on Stripped Graphite Film] [Illustration: Section of Wire Painted with a Stimulative Carbonaceous Paint] [Illustration: Corroded and Pitted Surface of Plate Painted with Stimulative Paint]