[NA023164], Technical Note, Thomas Alva Edison, December 1st, 1888
https://edisondigital.rutgers.edu/document/NA023164
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Title
[NA023164], Technical Note, Thomas Alva Edison, December 1st, 1888
Editor's Notes
Phonograph sketches followed by undated patent draft sometime between 881201 and 890331: Patent##To give the theory or the reactions as that is impossible in the present state of chemistry & besides is unnecessary for carrying out my invention commercially##I preferabley dehydrogenize the filiment by immersing them in common Kerosene in wich is disolved one part Chloride of sulphur to 20 of Kerosene and allow them to remain for 100 hours-- The filiment isn ow nearly infusible [overstruck text] It is then removed from the bath further treated in a batch containing acid & water 5 parts of acid to 95 water it is so greatly deydrogenized & the sulphur left in by the reactions is removed by oxidization that the filiment does not fuse or distort during carbonization##another method of dehydrogenizing is to use a Pentacholride of Antimony disolved in Chloride of Ethyl in about the same proportions as with the Chloride of Sulphur, owing to the great variability of the original material the best proportions must be determined for each lot or kind of maerial when the pentachloride is used Ocychloride of Antimony will be let in the ores of the filiment this may be disolved out by Hydrochloric acid. A subsequent treatment by nitric acid improves the character of the filiment still further--##[overstruck text] The filiment may be dehydrogenized by Nitric acid alone [overstruck text] If the action of the reagent is gradual##To the chemist there are innumerable methods of dehydrogenizing these asphaltic filiments to the point of non fusibility I only mention a single method which I have found simple & effective##The 2nd method to the partial dehydrogenizing of the Asphaltic material before formation into filiments-- [overstruck text]##The materials say solid Asphalt is powdered very fine & thrown into ordinary commercial ntric adic & stirred. A strong evolution of nitrous fumes takes place the Hydrogen of the Asphalt being oxidized by the O of the Nitric acid and it is probable that an oxidization of the remaining Hydrocarbon also takes place-- The whole cakes together by the heat of the reaction after no more fumes are gien off-- the lump is dried an repowdered and put in fresh and this takes place seveal times until no appreciable reduction of the nitric acid takes place the powder is then washed in water and [overstruck text] repowdered to 200 mesh screen & thoroughly dried-- The resultant powdered is then moistened with a solvent which varies according to the original source from which the Asphaltic material was obtained-- In the caseof ordinary solid asphalt the powder after is treatment with nitric acid is soluble in Chloroform and also warm Chloral Hydrate. To form the filiments I disolve the powder in Chloroform filter the solution then evaporate or distill off the chloroform to the consistency of Molasses & then add 10 parts by Chloral Hydrate to 90 parts of the powder & still further evaporate until it reaches the consistency of stiff pitch the [overstruck text] lump is after kneeding through the fingers to remove as much Chloroform as possible is placed in the squirting press the chamber of which is warmed to about 250 fahr [overstruck text] to cause the Chloral Hydrate to act readily the filiment are then easily squirted & retain their shape perfectly during carbonization.
Author
Date
1888-12-01
Type
Subject
Folder/Volume ID
NA023-F
Microfilm ID
99:395
Document ID
NA023164
Publisher
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University