Toinen linkki kertoo, että typpihapon sijaan voisi käyttää fosforihappoa sokerin "kuivaamiseen". "Töhnä" sekoitetaan veteen ja muste on valmista. Onnistuuko?
Simple Carbon Ink.
Dissolve 30 grains of sugar in 30 grains of water, to which add a few drops of concentrated sulphuric acid. Upon heating this mixture the sugar becomes carbonized by the acid, and when applied to the paper it leaves a coating of carbon which cannot be washed off. This stain is rendered more perfect by the decomposing action of the ink itself upon the paper, and thus resists the action of chemical agents.
Dick's Encyclopedia of Practical Receipts and Processes, [no date] circa 1870
The suggestion relative to the mode of applying carbon to these purposes, which it is intended more particularly now to enunciate, depends on the fact of the separation of carbon from organic compounds rich in that element, sugar, gum, etc., by the combined operation of heat and of chemical reagents, such as sulphuric and phosphoric acids, which exert a decomposing action in the same direction. [...]