And you'l easily believe, that in many changes of Colour, that happen upon the Dissolutions of Metalls, and Precipitations made with Oyl of Tartar, and the like Fix'd Salts, there may Intervene a Coalition of Saline Corpuscles with the Particles of the Body Dissolv'd or Precipitated, if you examine how much the Vitriol of a Metall may be Heavier than the Metalline part of it alone, upon the Score of the Saline parts Concoagulated therewith, and, that in Several Precipitations the weight of the Calx does for the same Reason much exceed that of the Metall, when it was first put in to be Dissolv'd.
"Experiments and Considerations Touching Colours (1664)"
Robert Boyle
Of the Adventitious Colours of Metalline Bodies the Chief sorts seem to be these three.
"Experiments and Considerations Touching Colours (1664)"
Robert Boyle
And as Metalline, so likewise Mineral Solutions may produce Colours differing enough from those of the Liquors themselves.
"Experiments and Considerations Touching Colours (1664)"
Robert Boyle