1980. Various prepared articles might be mentioned as of frequent or occasional use. Scoria from a forge is used for forming a platform impervious to worms, on which to place pots of plants. Soaper's ashes or waste is used for the same purpose. The use of gravel and sand is very general; fine sand, uncontaminated with ferruginous matter, is particularly useful in propagating heaths and other delicate plants by cuttings. Oyster shells are used as crocks or sherds for covering the hottom-holes of pots; quicklime in powder or infusions to destroy vermin, especially worms. Tobacco and other prepared matters are also used for the same purpose. Moss is used in packing and for other objects; tanner's bark for its heat and fermentation.