From this point of view I have studied more than a hundred substances belonging to different chemical systems and always with essentially the same
result. I will give here a short summary of the substances tested.
Simple substances (S, Si, Zn, Fe, Al, Pb, Sb); oxides (SiO2, MgO, MnO2, PbO, Sb2O3, Fe2O3, Ag2O, HgO, U3O8); hydroxides (B(OH)3, NaOH, Ba(OH)2,
Al(OH)3); inorganic chlorides (Na, K, NH4, Ca, Mg, Al, Fe, Co, Cu, Hg); chlorates (K, Ba); potassium bromide, potassium iodate; nitrates (K, Ca, Ba,
Pb, Ag, Cu, U); phosphates (K, Na, NH4, Fe); sulfides (K, Hg); sulfite (Na); sulfates (K, Ca, Mg, Ba, Zn, Fe, Mn, Cu); carbonates (Na, K, Ca, Mg, Fe);
silicates (K, asbestos); ammonium molybdate, potassium permanganate, potassium ferricyanide and potassium ferrocyanide, oxalic acid, tartaric acid,
citric acid, quinic acid, tannic acid, uric aid, picric acid, phenolphthalein; oxalates (NH4, Mn); acetates (Pb, Cu); amides (urea, asparagines);
higher alcohols and carbohydrates (mannite, dulcite, sucrose, galactose, inulin, dextrin, amylose); proteins (egg, albumin, peptone, hemoglobin);
trioxymethylene, chloral hydrate, hydroquinone, resorcin, pyrogallol, aniline dyes (gentian violet, chrysoidin, etc.); finally a series of chemically
undefined substances (bone meal and blood meal, soil, kieselguhr).
Some of these substances can also carry down carotin from its petroleum ether solution (HgCl2, CaCl2, PbS, etc.). Many bodies decompose the pigments
adsorbed on them. Some, for example (MnO2, KMnO4, U3O8), destroy the chlorophyll completely, obviously by oxidation. Others act on the chlorophyllines
in the well-known manner of acids; these include the acids mentioned, acid salts, and many neutral salts whose water solutions can acquire an acid
reaction by hydrolysis. |