These are called COLLECTIVE NOUNS. They properly belong under common
nouns, because each group is considered as a unit, and the name
applied to it belongs to any group of its class.


[Sidenote: _Names for things thought of in mass._]

6. The definition given for common nouns applies more strictly to
class nouns. It may, however, be correctly used for another group of
nouns detailed below; for they are common nouns in the sense that the
names apply to _every particle of similar substance_, instead of to
each individual or separate object.

They are called MATERIAL NOUNS. Such are _glass_, _iron_, _clay_,
_frost_, _rain_, _snow_, _wheat_, _wine_, _tea_, _sugar_, etc.

They may be placed in groups as follows:--

(1) The metals: _iron_, _gold_, _platinum_, etc.

(2) Products spoken of in bulk: _tea_, _sugar_, _rice_, _wheat_, etc.

(3) Geological bodies: _mud_, _sand_, _granite_, _rock_, _stone_, etc.

(4) Natural phenomena: _rain_, _dew_, _cloud_, _frost_, _mist_, etc.

(5) Various manufactures: _cloth_ (and the different kinds of cloth),
_potash_, _soap_, _rubber_, _paint_, _celluloid_, etc.