Colloidal suspensions contain particles of one material (a solid or a liquid) dispersed in another (which can be solid, liquid or gaseous).

ECONOMIST: A new way to build complicated materials, micron by micron

Households with oil-fired central heating, and those using solid fuel or liquid petroleum gas to heat their homes, are much more likely to be in fuel poverty than "on-grid" households.

BBC: Winter Fuel Allowance Payments Bill

Coal ash is disposed of either as a liquid that goes into large surface impoundments or as a solid that is placed into landfills.

FORBES: Coal Ash Spilling Into Obama and Romney Race

They are in remarkable condition, or at least they were until the bats moved in and began spreading liquid and solid waste with gay abandon.

ECONOMIST: Bat raves