O'Reilly v. Morse

Citation: O’Reilly v. Morse, 56 U.S. (15 How.) 62 (1853).

A claim for the “use of the motive power of the electric or galvanic current, which I [Morse] call electro-magnetism, however, developed, for making or printing intelligible characters, signs or letters at any distances, being a new application of that power” was held not patentable because the claim was “too broad and covers too much ground.”

The court reasoned that one cannot get a patent monopoly on an effect or a law of nature, viz., electric current.