It is easily conceived, that the Deflagration of nitre was likely to be first noticed in those countries where it is the spontaneous and abundant production of the earth, which is the case on the elevated desarts of Tartary and Thibet, and on the low and extensive plains of India and China.
"Travels in China, Containing Descriptions, Observations, and Comparisons, Made and Collected in the Course of a Short Residence at the Imperial Palace of Yuen-Min-Yuen, and on a Subsequent Journey through the Country from Pekin to Canton"
John Barrow
Deflagration is the burning of a substance with explosive violence, generally due to excess of oxygen.
"The Elements of Blowpipe Analysis"
Frederick Hutton Getman
Therefore the volume of powder is to the volume of gas produced by its Deflagration as 1 to 400. The frightful force of this gas, when it is compressed into a space 4,000 times too small, may be imagined.
"The Moon-Voyage"
Jules Verne