Gas chamber carbon monoxide as the lethal agent. Sometimes a box filled with anesthetic gas is used to anesthetize small animals for surgery or euthanasia. Gas chamber A gas chamber is an apparatus for killing humans or other animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. The most commonly used poisonous agent is hydrogen cyanide; carbon dioxide and carbon monoxide have also been used. Gas chambers were used as a method of execution for condemned prisoners in the United States beginning in the 1920s and continue to be a legal execution method in
Lawn mower less expensive models, and heavier steel on more expensive models for durability. Other deck materials include aluminium, which does not rust and is a staple of higher priced mowers, and hard composite plastic, which does not rust and is lighter and less expensive than aluminium. Electric mowers typically have a plastic deck. Riding mowers typically have an opening in the side or rear of the housing where the cut grass is expelled, as do most rotary lawn mowers. Some have a grass catcher attachment at the opening to bag the grass clippings. Mulching mowers Special mulching blades are available for