and fuel in [steam] engines” (i.e., the Watt patent), being neither “machinery” nor a
“substance[] (such as medicine[]) formed by chemical and other processes,” was not
within the Statute of Monopolies. Id. at 481-82. In contrast, Lord Chief Justice Eyres,
who believed processes had long been a valid subject of patents, urged that “two-thirds,
I believe I might say three-fourths, of all patents granted since the statute [of
Monopolies] passed, are for methods of operating and of manufacturing . . . .” Id. at
494-95 (emphasis added). He agreed that “[u]ndoubtedly there can be no patent for a
mere principle; but for a principle so far embodied and connected with corporeal
substances . . . I think there may be a patent.” Id. at 495 (emphasis added). Justice
Rooke also noted that Watt’s method was within the statute because it was connected
with machinery: “What method can there be of saving steam or fuel in engines, but by
some variation in the construction of them?” Id. at 478. The Justices who believed
process patents were valid spoke in terms of manufacturing, machines, and
compositions of matter, because the processes they believed fell within the statute were
processes that “embodied and connected with corporeal substances.” Id. at 495.
In 1799, on appeal from another case involving the same Watt patent, the validity
of such process patents were upheld. Hornblower v. Boulton (K.B. 1799), 8 T.R. 95.
There, Chief Justice Lord Kenyon stated that “it evidently appears that the patentee
claims a monopoly for an engine or machine, composed of material parts, which are to
produce the effect described; and that the mode of producing this is so described, as to
enable mechanics to produce it. . . . I have no doubt in saying, that this is a patent for a
manufacture, which I understand to be something made by the hands of man.” Id. at
99. Justice Grose agreed, finding that “Mr. Watt had invented a method of lessening
2007-1130 11