Abstract: A water-soluble glass treating agent consisting essentially of, by weight: 55 to 80% of SiO.sub.2, 19.5 to 42% of Na.sub.2 O and 0.5 to 3% of Ag.sub.2 O (conversion for AgNO.sub.3) is disclosed. Also disclosed is a water-soluble glass treating agent further containing, by weight: 0.5 to 30% of Al.sub.2 O.sub.3 in the above compositions. These glass water treating agents are glass free from boron constituent but which functions to kill or suppress bacteria and micro-organisms and are low in cost because it is simple in the composition of glass which is composed principally of three constituents at max. That agent which contains Al.sub.2 O.sub.3 functions to increase concentration of Ag in glass and to decrease the deliquescent property of glass.

Abstract: A treating method of preventing the putrefaction and emission of rancidity of water-contained cutting or grinding oil by placing in the oil a treating bag member wherein solids comprised of water-soluble glass composition containing Ag.sup.30 ion in the composition thereof are wrapped in water-permeable fiber cloth. The method makes it possible to suppress the development of microbes forming which cause the putrefaction and rancidity of oil by the action of Ag.sup.30 ion so as to prolong the service period of the oil by a substantial degree and also to stabilize the effect by making Ag.sup.30 ion flow out in generally constant relation with lapse of time.