R. Austin Freeman, A Silent Witness — Chapter 22 (1915)
“ Roughly speaking, by the volatilization of a liquified gas—ammonia, in the case of the sheep. But behold! The very man whom we are suspecting of being the agent in this crime is a man who has command of large quantities of a liquefied gas, and who has hired a mineral water factory for no apparent reason and put the premises to no apparent use. ”
