March 26th 1896.
The Electrical Engineer
Mail and Express Building
New York
Dear Sirs :-
Further experiments with the fluorescence of different chemicals under the influence of the X ray have added a few more to the list already published. The following fluoresce:- Cadmium Tungstate, Tungstate of Zinc, Lithia Benzoate, Tannate Lead, Carbonate Lead, Salicylate Potassium, Carbonate Silver, Sodium Salicylate, Sodium Carbonate, Sodium Tungstate, Zinc Acetate, Zinc Chloride, Zinc Carbonate, Molybdate Zinc, Benzoic Acid, Malic Acid, Diphenylamine, Ruffigallic Acid, Pyridin Nitrate. I have so far found no salt in the following metals to fluoresce:- Aluminum, Antimony, Arsenic, Boron, Beryllium, Bismuth, Cerium, Chromium, Cobalt, Copper, Gold, Iridium, Magnesium, Manganese, Nickel, Tin, Titanium. The crystals of the following chemicals give spots of light when held close to the bulb within a dark box. The light has the glow worm color of phosphorence and is due to the electric discharge and not to the X Ray:-Ammonium, Sulphocyanide, Calcium Formate, Calcium Nitrate, Iron Citrate, Silver Nitrate, Soda, Lime, Zinc Cyanide, Zinc Hypermanganate, Zinc Valerate.
With plates of fluorite I have found that the phosphorescence penetrates the plate very slowly, if held before a florescing tube for one minute the phosphorescence penetrates for 1/16 of an inch deep in the plate. This part when held edgewise is brilliant, beyond is dark.
Yours truly
Thos. A. Edison
R[andolph]

Download CSV | JSON