| 摘要 |
Stonework, enamelled and similar articles, such as garden walls having lime accretions, moss, or rust stains and baths and porcelain objects, are cleaned with an aqueous liquid containing phosphoric acid, sulphuric acid, and hydrochloric acid. The compositions may also contain other organic or inorganic acids which alone or in the mixtures dissolve rust, lime and such-like superficial impurities. Lactic acid and citric acid are specified. Colouring matter and perfume may also be present. The compositions may be in the form of paste by addition of kaolin, potato meal or both. Both the liquid and paste compositions are preferably applied with a paintbrush, and after allowing to remain for a time or immediately after, according to the object being cleaned, the latter is then thoroughly washed with water. |
