Frederick Langenheim
1846, January (patent), 1847, February (published)
22. For an Improvement in Coloring Daguerreotype Plates, by fixing the Colors thereon

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"22. For an Improvement in Coloring Daguerreotype Plates, by fixing the Colors thereon", American Patents, Journal of the Franklin Institute of the State of Pennsylvania, and American Repository, February, 1847, p.105. Patent was issued in January, 1846.
 
22. For an Improvement in Coloring Daguerreotype Plates, by fixing the Colors thereon; Frederick Langenheim, Philadelphia, Pennsylvania, January 30.
 
The patentee says, "In the invention of Isenring, for coloring plates, for which letters patent have been obtained, a difficulty arose in making the colors adhere, and it was found in practice that after a little handling, the color came off, and the picture was thus defaced. To remedy that defect is the object of my improvement.
 
"Either before the plate receives the color, or at the same time, I cause an impalpable powder of gum damarum,or other suitable resinous gum, to cover the parts to be colored, in the manner described in the patent granted to me as the assignee of Isenring, viz: by placing the plate in a close vessel, face up, with those parts covered that are not to be colored, and then filling the atmosphere contained in said vessel with the powder of gums above named, and allowing a sufficient quantity to settle, for the purpose intended : after the color is laid on the plates I submit it to a sufficient degree of heat to fuse the gum, which causes the color to adhere."
 
Claim. "Having thus fully described my improvement, what I claim therein as new and desire to secure by letters patent, is fixing the colors on the plates by means of gum, applied substantially in the manner and for the purpose set forth."
 
LL/39308