Mitchell v. Tilghman - 86 U.S. 287 (1873)
U.S. Supreme Court
Mitchell v. Tilghman, 86 U.S. 19 Wall. 287 287 (1873)
Mitchell v. Tilghman
86 U.S. (19 Wall.) 287
APPEALS FROM THE CIRCUIT COURT FOR
THE SOUTHERN DISTRICT OF NEW YORK
What R. A. Tilghman, of Philadelphia, claimed as his invention under the letters patent granted to him of January 9, 1854, was the process of manufacturing fat acids and glycerin from fatty or oily substances by the action of water at a high temperature and pressure.
Two conditions, viz., that the heating vessel must be kept entirely full of the mixture of fat and water and that no steam or air must be allowed to accumulate in the vessel employed to impart the heat, were material and indispensable conditions of Tilghman's patented method.