The speech standard of the Ming and Qing empires was called Mandarin language by European missionaries, translating the Chinese name Guanhua (the language of the officials) for this speech standard, which was current already in the Ming Dynasty.
Producer gas is made by blowing air through an incandescent fuel bed (commonly coke or coal) in a gas producer. The reaction of fuel with insufficient air for total combustion produces carbon monoxide (CO); this reaction is exothermic and self-sustaining.
The fuel in a gas explosion may result from release of a flammable gas normally used as a fuel or in industrial processes (e.g., methane, cyclohexane) or from accumulation of unburned pyrolysis and combustion products in a compartment fire.