particular ingredients, since those processes that include the selection
of particular ingredients necessitate search among compositions having
such ingredients. (See Rule 28.)

Example: A patent having a claim for a composition
consisting of a mixture of caoutchouc and casein, and a
claim for the process of preparing a rubberlike substance
which consists in adding undissolved raw caoutchouc to
casein and thoroughly mixing and kneading the mass, would
be classified according to the composition.

(35) Where a patent claims a product such as a specific article of
manufacture, or a specific composition of matter, and also claims a
process of general application for making one of the parts of the
article or one of the ingredients of the composition, the product claim
should control the classification. (See Rule 28.)

Example: If a patent claimed a woven textile fabric having
the yarns interlaced in a defined relation, and a process
of spinning a yarn utilized in the fabric; or if a patent
claimed a varnish composed of shellac, dissolved in wood
alcohol, and a pigment, and also contained a claim for
distilling wood to obtain the alcohol, the product claim
would control the classification in each instance, and the
process would be cross-referenced.

[1] All terms have a meaning in extension and in intension. The meaning
of a term in extension consists of the objects to which the term may be
applied; its meaning in intension consists of the qualities necessarily
possessed by objects bearing that name. The term "motors" in extension
means all motors--electric, gas, water, spring, weight, etc. "Motors" in
intension means instruments to convert some form or manifestation of
energy into periodical or cyclical motion of a body. As the intension
increases the extension decreases, and vice versa. There must be more
motors than there are electric motors, and electric motors have more
qualifications than are common to all motors. Comparison of arts and
instruments with respect to their extension and intension for
classification purposes should be made between comparable qualities. A
claim for a steam-engine may be very specific while a claim for a reaper
may be very broad; here there is no comparable relationship, and the
terms intensive and extensive do not have the relative significance most
useful in classification. But when a patent or application contains
claims for mechanism peculi