Ussher v Chamber of Mines [1912] ZATPD 140 (22 November 1912)

Patents.-Old Processes.-New Purpose.

An invention by which an old process is itsed for a new
purpose is patentable.

A certain mixture had been used for laying dust on the
surface, but had proved unsatisfactory: -Held, that
a process by which the mixture was successfully used
for laying dust in the underground workings of a
mine, was not a mere carrying forward of general
knowledge but was an invention which was patentable
.