Johnson, 1853, employed the rough and irregular surface produced by the fracture of cast iron or other brittle metal to form a water mark for paper by taking an impression therefrom on soft metal, gutta- percha, etc., and afterward transferring it to the wire cloth on which the paper is made.
Scoutteten, 1853, treated paper with caoutchoue dissolved in bisulphide of carbon, in order to render it impermeable and to prevent erasures or chemical action.
Ross, 1854, invented water-lining or printing the denomination of the note in colors while the pulp was yet soft.
Evans, 1854, commingled a lace or open-work fabric in the pulp.
Courboulay, 1856, mixed the pulp and applied to the paper salts of iodine or bromine.
Loubatieres, 1857, manufactured paper in layers, any or all of which might be colored, or have impressions or conspicuous marks for preventing forgery.
Herapath, 1858, saturated paper during or after its manufacture with a solution of a ferrocyanide, a ferriccyanide, or sulphocyanide of potassium, sodium, or ammonium.
Seys and Brewer, 1858, applied aqueous solutions of ferrocyanide of potassium or other salts, which formed an indelible compound with the ferruginous base of writing ink.
Sparre, 1859, utilized opaque matter, such as prussian blue, white or red lead, insoluble in water and stenciled on one layer of the paper web, forming a regular pattern; this was then covered by a second layer of paper.
Moss, 1859, invented a coloring matter prepared from burned china or other clay, oxide of chromium or sulphur, and combined it with the pulp.