Inks containing also logwood, fustic, Brazil wood, or madder, were all of them more or less employed some years ago. Their color phenomena, following long periods of time, is much the same. Tests as prescribed in the accompanying table for such inks will serve to classify them preliminary to subsequent and more certain ones. LOGWOOD. FUSTIC. Concentrated Hydrochloric Acid Red-yellow Red Dilute " " Reddish Yellow-Brown Concentrated and dilute Nitric Acid Red Red-Yellow " Sulphuric Acid . . Black Dark Purple Dilute " " Red Brown Purple Potassium Chromate . . . . Black Stannous Chloride Violet Yellow Tartaric Acid . . . . . Gray-Brown Yellow Sulphate of Copper . . . . Dark Gray Tannin . . . . . . Yellow-Red Yellow Potash Dark Red Yellow Potassium Permanganate Light-Brown Yellow " Iodide . . . . . Red-Yellow Pyrogallic Acid . . . . Yellow-Brown Yellow Chrome-yellow . . . . . Dark Violet Sodium (Salt) Violet Red Sulphate of Iron Gray to Black Alum . . . . . . . Violet Red,Brown. Faint Red BRAZIL WOOD. MADDER. Concentrated Hydrochloric Acid Light Red Pale Yellow Dilute " " Light Red Pale Yellow Concentrated and dilute Nitric Acid Dark Purple Pale Yellow " Sulphuric Acid . . Red Pale Yellow Dilute " " Purple Pale Yellow Potassium Chromate . . . . - - Stannous Chloride Light Red Light Red Tartaric Acid . . . . . Red Yellow Pale Yellow Sulphate of Copper . . . . - - Tannin . . . . . . No Change Pale Yellow Potash Crimson Light Red Potassium Permanganate - - Iodide . . . . . - - Pyrogallic Acid . . . . - - Chrome-yellow . . . . . - - Sodium (Salt) - Red Sulphate of Iron Dark Violet - Alum . . . . . . . - Faint Red CHAPTER XIX. FRAUDULENT INK BACK GROUNDS. DETECTION OF ALTERATIONS IN DOCUMENTS BY CHEMICAL TESTS WHICH APPLY SOLELY TO THE PAPER--ACCURACY OF RESULTS OBTAINED BY USE OF IODINE EXCELS THAT OF ALL OTHER CHEMICALS--IT APPLIES BEST TO LINEN PAPER--MODERN HARD PAPER DOES NOT GIVE COMPLETE INFORMATION--EFFECT OF IODINE ON MARKS MADE BY A STYLUS OR GLASS PEN.