Through a naturalist’s eyes
"In times past when every animal and plant was believed to have a use for mankind, freshwater sponges were not exempt. They were dried and ground into a powder that was used for a variety of purposes. The sharp fragments of teh silicaceous spicules are midly abrasive and cause irritation and inflammation when rubbed on the skin. So, the powder was used masochistically as rouge to redden girls' cheeks."