The subject of this paper is in quotation marks, for this popular but inelegant phrase comes as near expressing my subject as any I can find.
In the beginning, let us consider what gas or gases are found in the stomach, although this has been investigated and the knowledge gained has resulted in little or no good. Observations have identified carbon dioxid. hydrogen, methane and acetylene, but in a vast majority of instances simple atmospheric air alone is present. It is only in the presence of true fermentation that carbon dioxid and other gases are found, and this fermentation lakes place only when stasis is present.
Usually the gas, as I say, is atmospheric air swallowed with food, and this is its source in nine cases out of ten—yes, in ninety-nine out of a hundred. It is still a common practice among physicians to allow patients to think that food
GRAYSON TW. "GAS ON THE STOMACH". JAMA. 1912;LVIII(21):1563-1564. doi:10.1001/jama.1912.04260050239003