The Galaxy 1, 1873
[...]
When different colors are mixed together, the result is not the destruction of any of the coloring elements, or their chemical combination. The microscope shows that the particles of each of the colors entering into the mixture remain entirely separate and unchanged.
[...]
Dr. Balard has analyzed the ink on a manuscript of the year 910, and finds that it is of a composition similar to the inks now in general use; and MM. Coupier and Collin have produced an ink which resists the action of nitric and hydrochloric acids, chlorine, and bromine, though it is not proof against alkalies.
[...]
M. Guignet, of the Chemical Society of Paris, thus accounts for the black spots which often appear on textures dyed with cochineal. It has been supposed that these spots are owing to the presence of iron; but M. Guignet says that they are due to the formation of the carminate of calcium, or to the presence of lime in the water used in dyeing. Carminate of calcium is a black powder, soluble in water, and soluble, but not decomposable, in nitric acid.
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