| http://www.w3.org/ns/prov#value | - Air treating gels of this type are known in the art, for example from U.S. Pat. No. 2,691,615 which teaches the use therein of gelling agents such as alginates, gelatin, pectin, agar-agar, karaya, tragacanth, starch, nitrocellulose compositions, and the like.
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