To Cleanse Bath Sponges.

Progress, Volume VI, Issue 1, 1 November 1910, Page 449

To Cleanse Bath Sponges.

1. Unused sponges: Turning them repeatedly, they should be beaten with a little wooden stick, to remove any sand they may contain, then they are laid in 0.5 to 1 per cent, hydrochloric acid several, times until no more lime is dissolved. Next they should be gently squeezed out and placed in a permanganate of potash solution (1 part to 2 parts per thousand), allow them to lie in it for 1 to y 2 an hour, press them out again and then place them in an aqueous solution of sulphurous acid (the latter dissolved from acid sulphite of soda in water) and hydrochloric or sulphuric acid added (small quantities) sulphuric acid mixed with sulphurous acid (for large quantities). After 15 minutes, squeeze the sponges out and place them in 2.5 to 5 per cent, hydrochloric acid until the remains of the peroxide of manganese still adhering to them are removed. They are now of a straw yellow colour; if it is, desired to have them still lighter, the entire process is repeated, the sponges are then rinsed, pressed . out, and dried at a moderate temperature. Brown spots may be removed by laying the cleansed sponge in a 20 per cent, oxalic acid solution for a longer period. The sponge is now almost white or yellowish white, after drying in the air. If they should look somewhat brown, on account of their contact with alkalis, lay them for a time in weakly ammoniacai water, to which some peroxide of hydrogen has been added. 2. Used sponges: To be treated at certain intervals. First of all, the fatty substances are removed by repeated soaking of the sponges in 1 to 2 per cent, carbonate of soda solution, at about 120 deg. F. (no concentrated or boiling solutions) ; finally, also, in aqueous or alcoholic ammonia. Bleach as above.