Sentence:  Police said that he bought a 54-gallon drum of poisonous methyl alcohol, often used for hot-rod fuel, and mixed it with well water, peach flavoring, regular moonshine and a "beading oil" calculated to make it foam when shaken. Seventy-seven gallons were delivered. Within hours Atlanta's Grady Negro Clinic began to fill with men and women who panted, <WSD>frothed at the mouth</WSD> and writhed in horrible convulsions. 
Meaning of the word marked with <WSD> tags:  To spew saliva as froth.