It was not that I had or have any quarrel with the creatures I have named, or would have them other than they are-carrion-eaters and scavengers, Nature's balance-keepers and purifiers.
"Afoot in England"
W.H. Hudson
A, furnace; C, retorts containing coal; T, gas-tubes leading to B, the hydraulic main; D, condensers; O, washers, with a spray of water, and sometimes coke; M, purifiers-ferric oxide or lime; G, gas-holder.
"An Introduction to Chemical Science"
R.P. Williams
Common oak chips as purifiers.
"The Wonder Island Boys: Exploring the Island"
Roger Thompson Finlay